3x + ky = 8
X – 2ky = 5
are simultaneous equations where k is a constant.
b) Given that y = 1/2 determine the value of k.

Answers

Answer 1

Answer:

(a): x is 3 and ky is -1

(b): k is -2

Step-by-step explanation:

Let: 3x + ky = 8 be equation (a)

x - 2 ky = 5 be equation (b)

Then multiply equation (a) by 2:

→ 6x + 2ky = 16, let it be equation (c)

Then equation (c) + equation (b):

[tex] { \sf{(6 + 1)x + (2 - 2)ky = (16 + 5)}} \\ { \sf{7x = 21}} \\ { \sf{x = 3}}[/tex]

Then ky :

[tex]{ \sf{2ky = 3 - 5}} \\ { \sf{ky = - 1}}[/tex]

[tex]{ \bf{y = \frac{1}{2} }} \\ { \sf{ky = - 1}} \\ { \sf{k = - 2}}[/tex]

Answer 2

Simultaneous equations are used to represent a system of related equations.

The value of k when [tex]y = \frac 12[/tex] is -2

Given that:

[tex]3x + ky = 8[/tex]

[tex]x - 2ky = 5[/tex]

[tex]y = \frac 12[/tex]

Substitute [tex]y = \frac 12[/tex] in both equations

[tex]3x + ky = 8[/tex]

[tex]3x + k \times \frac 12 = 8[/tex]

[tex]3x + \frac k2 = 8[/tex]

[tex]x - 2ky = 5[/tex]

[tex]x - 2k \times \frac 12 = 5[/tex]

[tex]x - k = 5[/tex]

Make x the subject in [tex]x - k = 5[/tex]

[tex]x = 5 + k[/tex]

Substitute [tex]x = 5 + k[/tex] in [tex]3x + \frac k2 = 8[/tex]

[tex]3(5 + k) + \frac k2 = 8[/tex]

Open bracket

[tex]15 + 3k + \frac k2 = 8[/tex]

Multiply through by 2

[tex]30 + 6k + k = 16[/tex]

[tex]30 + 7k = 16[/tex]

Collect like terms

[tex]7k = 16 - 30[/tex]

[tex]7k = - 14[/tex]

Divide both sides by 7

[tex]k = -2[/tex]

Hence, the value of constant k is -2.

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Related Questions

Geometry edulastic question

Answers

9514 1404 393

Answer:

  n = 16

Step-by-step explanation:

Angle ABC is the sum of its parts.

  ∠ABC = ∠ABF +∠FBC

  159° = (7n +20)° +(2n -5)°

  159° = 9n° +15° . . . . . . . . . . . . . . collect terms

  144° = 9n° . . . . . . . . . . subtract 15°

  16° = n°

  n = 16

There are 3200 students at Lake High School and 310 of these students are sophomores. If 38 of the sophomores are in favor of the school forming a crew team and 34 of the remaining students (not sophomores) are also in favor of forming a crew team, how many students are opposed to this idea?

Answers

Answer: 3128 students

Step-by-step explanation:

Total no of students in the school : 3200

No of sophomores in favor of the school forming a crew team : 38

No of the remaining students in favor of forming a crew team : 34

Total students in favor of forming a crew team = 38+34= 72

No of students against it : Total students - Students in favor

                                          = 3200-72 = 3128 students

Pls help area geometry! I’ve got 40 steps to do in a day :(

Answers

Answer:

26 cm^2

Step-by-step explanation:

(b*h)/2 is the area formula of a triangle (use it for your other questions!)

base here is the bottom-most side, the one that is 13 degrees. the side that is 4 cm is the height.

13*4 = 52 and 52/2 = 26

Area is 26

Area is 26 I think sorry if not

The amount of grain that a shape will hold is called the surface area.

True
False

Answers

false because the grain the shape will hold is called the surface area

Answer:

false =D

Step-by-step explanation:

Square inscribed in a circle with radius 16.

I’ll mark u as a brainliest!!

Answers

Answer:

if your trying to find the area of the square it's 1024 if your trying to find the circumference of the circle it's 32π ( also known as 32 x pi)

solve for x.
solve for x.
solve for x.

Answers

Answer:

[tex]x=10[/tex]

Step-by-step explanation:

A secant is a line segment that intersects a circle in two places. One property of a secant is the product of the lengths ratio. This ratio can be described as the following, let ([tex]inside[/tex]) refer to the part of the secant that is inside the circle, and ([tex]outside[/tex]) refer to the part that is outside of it. ([tex]total[/tex]) will refer to the entirety of the secant or ([tex]inside+outside[/tex]). The numbers (1) and (2) will be used as subscripts to indicate that there are two different secants.

[tex](outside_1)(total_2)=(outside_2)(total_2)[/tex]

Substitute,

[tex](outside_1)(total_2)=(outside_2)(total_2)[/tex]

[tex](outside_1)(inside_1+outisde_1)=(outside_2)(inside_2+outside_2)[/tex]

[tex](6)(6+x+5)=(7)(7+x+1)[/tex]

Simplify,

[tex](6)(6+x+5)=(7)(7+x+1)[/tex]

[tex]6(x+11)=7(x+8)[/tex]

[tex]6x+66=7x+56[/tex]

Inverse operations,

[tex]6x+66=7x+56[/tex]

[tex]66=x+56[/tex]

[tex]10=x[/tex]

using the graph, determine the coordinates of the roots of the parabola​

Answers

Answer:

(-8, 0) and (-2, 0)

Step-by-step explanation:

The root of a parabola are the places at which the parabola intersects the x-axis. As one can see, on the graph these points are the following: (-8, 0) and (-2, 0). Thus, the roots of the parabola are (-8, 0) and (-2, 0).

Answer:

-8 and -2

Step-by-step explanation:

Hello!

The roots of the parabola are the points where the graph intersects the x-axis. The x-axis is the equation y = 0.

There are two roots for this parabola, as the vertex is lower than y=0, and it opens up.

The two points of intersection are:

(-8,0)(-2,0)

Therefore, the roots of the parabola are -8 and -2.

find the measure of the indicated angle to the nearest degree​

Answers

[tex]\boxed{\sf sin\theta=\dfrac{P}{H}}[/tex]

[tex]\\ \sf\longmapsto sin\theta=\dfrac{38}{53}[/tex]

[tex]\\ \sf\longmapsto sin\theta=0.7[/tex]

[tex]\\ \sf\longmapsto sin\theta=\dfrac{1}{1.4}[/tex]

[tex]\\ \sf\longmapsto sin\theta=\dfrac{1}{\sqrt{2}}[/tex]

[tex]\\ \sf\longmapsto sin\theta=sin45°[/tex]

[tex]\\ \sf\longmapsto \theta=45°[/tex]

How do you make x the subject of the formula?
I need help on this one
y= 7x-1​

Answers

Answer:

x=[tex]\frac{y+1}{7}[/tex]

Step-by-step explanation:

Hi there!

We want to make x the subject of the formula, which means to solve the formula for x

Here is the given formula:

y=7x-1

Our ultimate goal is to isolate x onto one side

Start by subtracting 7x from both sides

y-7x=-1

Subtract y from both sides to remove it from the left side

-7x=-y-1

Divide both sides by 7

x=[tex]\frac{-y-1}{-7}[/tex]

Simplify (factor -1 out of the numerator and denominator, then cancel it out)

x=[tex]\frac{-1(y+1)}{(-1)(7)}[/tex]

x=[tex]\frac{y+1}{7}[/tex]

Hope this helps!

Answer:

x = 1/7(y+1)

or

x = 1/7 y + 1/7

Step-by-step explanation:

y= 7x-1​

Solve for x

Add 1 to each side

y+1 = 7x-1+1

y+1 = 7x

Divide each side by 7

1/7(y+1) = 7x/7

1/7y + 1/7 =x

You are testing the claim that the proportion of men who own cats is larger than the proportion of women who own cats. You sample 170 men, and 70% own cats. You sample 190 women, and 40% own cats. Find the proportion of the pooled samples, ( p c pc ), as a decimal, rounded to two decimal places.

Answers

Answer:

The proportion of the pooled samples is 0.54.

Step-by-step explanation:

We have that:

70% of men own cats.

The proportion of men in the sample is:

[tex]\frac{170}{170+190} = 0.4722[/tex]

40% of women own cats.

The proportion of women in the sample is: 1 - 0.4722 = 0.5278

Proportion of the pooled samples

[tex]p = 0.7*0.4722 + 0.4*0.5278 = 0.54[/tex]

The proportion of the pooled samples is 0.54.

A rectangular drawing is enlarged by 30%. The original dimensions of this drawing are 16cm x 24cm.
Determine the scale factor, as a fraction that represents this enlargement. What are the new, enlarged
dimensions?

Answers

Answer:

Step-by-step explanation: Scale [tex]\frac{130}{100} = \frac{13}{10}[/tex]

New dimensions [tex]16 * 1.3 --- 24*1.3 =20.8 cm * 31.2 cm[/tex]

- 5x + x - 6x²
6x3 - 4 - 5 + 6x3 - 3x3

Answers

Is this all one equation?

If it isn't, here:

-6x ^ 2 - 4x <-- Equation 1

18 - 9 + 18 - 9 = 18 <-- Equation 2

If it is:

-5x + x - 6x ^ 2 + 6 * 3 - 4 - 5 + 18 - 9

-4x - 6x ^ 2 + 18 - 9 + 18 - 9

-4x - 6x ^ 2 + 18

Then we order it

-6x ^ 2 - 4x + 18

The solution to an inequality is graphed on the number
line.
What is another way to represent this solution set?
C OF
O {xx <4.5)
O {x| 4.5}
{x | x > 4.5)
O {x|x 2 4.5}
-5
0
1
2
3
4 5
Save and Exit
Next
SUOMI
Mark this and return

Answers

Answer is -5 because of a new internet connection with the park in the park lol lol that’s fine with us too lol I can’t wait to get it out of the park now lol that’s fine I’ll wait till tomorrow after I get off my work so

From the given number line, we have inequality as {x|x≤4.5}. Therefore, option B is the correct answer.

What are inequalities?

Inequalities are the mathematical expressions in which both sides are not equal. In inequality, unlike in equations, we compare two values. The equal sign in between is replaced by less than (or less than or equal to), greater than (or greater than or equal to), or not equal to sign.

Inequalities on a number line allow us to visualize the values that are represented by an inequality. To represent inequalities on a number line we show the range of numbers by drawing a straight line and indicating the end points with either an open circle or a closed circle.

From the given number line, we have inequality as {x|x≤4.5}

Therefore, option B is the correct answer.

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PLZ HELP!!!
Find the range of the following piecewise function.

Answers

Answer:

B

Step-by-step explanation:

the answer is B because, our range starts at 2 but does not include 2 and continues to infinity (x>8) does not have a boundary.

When Jonathan runs the 400 meter dash, his finishing times are normally distributed with a mean of 88 seconds and a standard deviation of 2.5 seconds. If Jonathan were to run 48 practice trials of the 400 meter dash, how many of those trials would be between 89 and 91 seconds, to the nearest whole number?

Answers

Answer:

3.18%

2 between 89   91

Step-by-step explanation:

*Probability-Between 3.18%

Z1=0.04 Z2=0.12

x-1 89

x-2 (not required) 91

µ 88

σ 25

Solve the triangle. Round to the nearest tenth when neccesary or to the nearest minute as appropriate. ​

Answers

Answer:

Here is the detailed answer below

Step-by-step explanation:

If mBAC = 90°, and mZDAC = 68°,
then mBAD = [?]

Answers

Answer:

22 degrees

Step-by-step explanation:

BAC=90 and DAC=68

DAC+BAD=BAC=90

so BAD=BAC=DAC

so BAD=90-68

= BAD=22 degrees

Answer:

The answer according to my calculations would be 22 degrees

Step-by-step explanation:

Fill in the box 22

determine the general term of this sequence -15:-11;-7;,,173

Answers

Answer:

UWUNOE BRO HUUZEM HIHUDHS

Step-by-step explanation:

6.
Ahmad claims that the difference of squares method of factoring can be used even when the values aren't perfect squares. An example of his thinking is shown.

Answers

Answer:

Below.

Step-by-step explanation:

a. (x - √5)(x + √5)

= x(x + √5) - √5(x + √5)

= x^2 + √5x - √5x - 5

= x^2 - 5.

b. 10 - 3x^2

= (√10 - √3x) (√10 + √3x)

(a) Ahmad's factorization is correct.

(b)  (√10 - √3x)(√10 + √3x)

Given equation as

x² - 5 = (x - √5)(x + √5)

What is a Perfect Square?

A Perfect Square is defined as when multiplying an integer by itself, we get a perfect square, which is a positive integer. In simple words, we can say that perfect squares are numbers that are the products of integers by themselves.

Solution of (a)

Taking RHS from the given equation

⇒ (x - √5)(x + √5)

⇒ x(x + √5) - √5(x + √5)

⇒ x² + √5x - √5x - 5

⇒ x² - 5.

So, RHS = LHS

Hence, Ahmad's factorization is correct.

Solution of (b)

⇒ 10 - 3x²

According to Ahmad's strategy  

⇒ √10(√10 + √3x) - √3x(√10 + √3x)

(√10 - √3x)(√10 + √3x)

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Let V(x) = -x2 + 2x - 4 and W(x) = -~3 + 2x2 + x +, 5. Find
V(x) + W(x).
ASAP

Answers

Answer:

-x3+x2+3x+1

Step-by-step explanation:

V(x) + W(x) = -x2 + 2x - 4 + -x3 + 2x2 + x + 5= -x3+x2+3x+1

Find EF
-----------------------------------------------

Answers

Answer:   6

===========================================================

Work Shown:

(whole length)*(external part) = (whole length)*(external part)

(EG)*(FG) = (SG)*(HG)

(2x+4)*(4) = (x+5)*(5)

8x+16 = 5x+25

8x-5x = 25-16

3x = 9

x = 9/3

x = 3

Use this x value to find EF

EF = 2x

EF = 2*3

EF = 6

For more information, search out "secant secant formula". It's not a typo that I wrote "secant" twice.

PLEASEEEE HELLLLP MEEEE

Answers

Answer:

c. 20/21

Step-by-step explanation:

You just multiply straight

3×7 = 21

4×5 =20

21/20 <---- and it can't be reduced farther than this.

Answer:

C. ²¹⁄₂₀

Step-by-step explanation:

OKOKOK DON'T WORRY I'M HERE :)))

--

When multiplying fractions, you multiply the numerators together and then multiply the denominators together.

The numerators here are 3 and 7. Multiply those and you get 21 (7 x 3 = 21).

The denominators here are 4 and 5. Multiply those and you get 20 (4 x 5 = 20).

Then you put the newly-multiplied numerator over the newly-multiplied denominator and you get ²¹⁄₂₀.

Hope this helped!!

m% of a number equals n. can you find the number?

Answers

Answer:

mn/100

Step-by-step explanation:

m/100 * n = number = mn/100

Assuming m and n are variables with no values.

please help me someone! asap!

Answers

Answer:

please help me to solve these qustions

PLEASE HELP WILL MARK BRAINLIEST!!!! You work for a consumer advocate agency and want to find the mean repair
cost of a washing machine. As part of your study, you randomly select 40
repair costs and find the mean to be $120.00. The sample standard deviation
is $17.50. The 99% confidence interval for the population mean repair cost is? A.(112.86, 127.14) B.(114.58, 125.42) C. (115.43, 124.57) D. (111.57, 128.43)

Answers

Answer:

The correct answer is - A.(112.86, 127.14)

Step-by-step explanation:

Given:

mean = $120

sd = $17.50

n = 40

Solution:

Confidence interval for a populationcan be express as mean +/- margin of error (E)

degree of freedom = n-1 = 40-1 = 39

confidence level (C) = 99% = 0.01

significance level = 1 - C = 1 - 0.01 = 0.99 = 99%

 by margin of error E = t×sd/√n = 2.58*17.50/√40

= 2.58*2.76

= 7.138 or 7.14

then the lower limit of mean = mean - E = 120 - 7.14 = $112.86

and, the upper limit of population mean = mean + E = 120 + 7.14 = $127.14


Times for an ambulance to respond to a medical emergency in a certain town are normally distributed with a
mean of 450 seconds and a standard deviation of 50 seconds.
Suppose there are 97 emergencies in that town.
In about how many emergencies are the response times expected between 400 seconds and 500 seconds?
31
33
47
66

Answers

Answer:

66

Step-by-step explanation:

The Empirical Rule states that 68% of data is between 1 standard deviation in a dataset of normal distribution, 95% falls between 2 standard deviations, and 99.7% between 3.

The mean is 450, and one standard deviation is between 450 ± 50 = 400 and 500. Therefore, we can say that 68% of the data falls between 400 and 500 seconds.

The data includes 97 emergencies, so we just need to find 68% of that, which is 0.68*97 = 65.96 (rounding up to 66)

There are 66 emergencies are the response times expected between 400 seconds and 500 seconds.

What is Addition?

The process of combining two or more numbers is called the Addition. The 4 main properties of addition are commutative, associative, distributive, and additive identity.

Given that;

mean = 450 sec

standard deviation = 50 sec

Hence, We get;

450-50 =400

450+50=500

Now, In Between 400 sec and 500 sec means one deviation above and one deviation below the mean, and it is 68%.

68% = 0.68

Thus,

0.68 x 97 = 65.96 ≈ 66

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find the missing side. Round it to the nearest tenth. ​

Answers

Answer:

37.3

Step-by-step explanation:

tan63 = opposite/adjacent = x/19

x = 19tan63 = 37.2895 = 37.3

Final Answer: x = 60

Formula used: [tex]b=\sqrt{c^2-a^2}[/tex]

a = 19

b = x

c = 63

solution

b = [tex]\sqrt{c^2-a^2}[/tex]

b = [tex]\sqrt{63^2-19^2}[/tex]

b = [tex]\sqrt{3,969 -361}[/tex]

b = [tex]\sqrt{3,608}[/tex]

b = [tex]\sqrt{60.0666}[/tex]

rounded off: 60.0 or just 60

x = 60

A metal rod will be cut into pieces that are each 1/56 meters long. The rod is 7/8
meters long how many pieces will be made from the rod? Write in simplest form.

Answers

7/8 = x/56

x = 7 x 7

so, 49/56 = rod

so, 49 pieces will be made

hope it helps :)

Help with step by step solution please

Answers

Answer:

5/2

Step-by-step explanation:

The square root of 5 divided by the negative square root of 5 equals -1. 7/2 - 1 = 5/2.

I just need to know if my answer is correct or not please!

Answers

yes, it’s correct!!

Answer:

Step-by-step explanation:

correct 100%

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