Which of the following is the most direct first step in solving the system of equations be-
low using the elimination method?
x + y = 4
2x - y = 2
That is, which of the following would be the first step in a method that would require the
fewest number of steps?
A
multiplying the second equation by -2
B
adding the two equations together
С
multiplying the first equation by -2
D
multiplying both equations by 2

65.4Step-by-step explanation:KHAN

Important formula:

[tex]N_t = N_0 (1/2)^\frac{t}{t_{1/2}}[/tex]

Here, you are trying to find Nt and you have N0 = 4.5g, t = 23 days, t1/2 = 30 days. Plug the values in and you should get 2.7g left after 23 days.

Answer:

Step-by-step explanation:

y = 600 * (1.04)¹⁵

= 600 * 1.80094351

= $ 1080.57

Answer:

H0 : μ ≤ x

H1 : μ > x

The hypothesis :

The null hypothesis, H0 : μ ≤ x

The alternative hypothesis, uses the Friday score samples to compare the hypothesis ;

The alternative hypothesis, H1 : μ > 8

For then null, the mean scores is assumed to be the same, and has such mean of Friday's test score takes the value of the population.

Let the population mean value = x

The alternative hypothesis is the claim that the sampled mean gives a greater value than the population mean :

H1 : μ > x

Answer:

-11/6

Step-by-step explanation:

To find the slope, we use the formula

m = ( y2-y1)/(x2-x1)

   = ( 8- -3)/( -6 - 0)

   = (8+3)/(-6-0)

  = 11 / -6

 = -11/6

Answer:

A = 5.6 m^2

Step-by-step explanation:

The area of a trapezoid is given by

A = 1/2 h( b1+b2) where h is the height and b1 and b2 are the lengths of the bases

A = 1/2 (2) (4+1.6)

A = 1(5.6)

A =5.6 m^2

Answer:

Step-by-step explanation:

b1 = 4 m   ; b2= 1.6m ; h = 2m

[tex]A =\frac{1}{2}h(b_{1}+b_{2})\\\\=\frac{1}{2}*2(4+1.6)\\\\=\frac{1}{2}*2*5.6\\\\=5.6 m^{2}[/tex]

Answer:

Step-by-step explanation:

[tex]\frac{sinxcos^3x-cos xsin^3x}{cos^42x-sin^42x} \\=\frac{sin x cos x(cos^2x-sin ^2 x)}{(cis^2 2x+sin^2 2x)(cos^2 2x-sin ^22x)} \\=\frac{2sin x cos x cos 2x}{2(1)(cos 4x)} \\=\frac{sin 2x cos 2x}{2 cos 4x} \\=\frac{2 sin 2x cos 2x}{4 cos 4x} \\=\frac{sin 4x}{4 cos 4x} \\=\frac{1}{4} tan 4x[/tex]

Answer:

x = 12 m = 87

Step-by-step explanation:

x = Dave

(7x + 3) + x = 99

8x + 3 = 99

      -3     -3

8x = 96

----    ----

8       8

  x = 12

7(12) + 3

84 + 3

   87

Dave has 12 dollars, Martha has 87.

here it is :)

do check properly, I have given step by step instructions:)

do give feedback on my answer, would appreciate it!

Answer:

900000

Step-by-step explanation:

[tex]30*10^{4}[/tex]

=3*10000

=30000

=30*30000

=900000

Answer:

I hope it is correct.. :)

Answer:

a

Step-by-step explanation:

vì số âm không nằm ở dưới

Answer:

-14

Step-by-step explanation:

12mn-8mt+9t²-6mt

12mn+9t²-14mt

the coefficient of mt is -14

The coefficient of the given expansion 4m(3n-2t)+3t(3t-2m)​ will be -14.

Expanded form is the term used in mathematics to refer to the process of expanding a number to convey the value of every digit and place value.

When a mathematical object is increased by a multiplier that is bigger in actual values than one, an expansion follows.

In another word, if you solve a factor by opening the bracket then you will go to get on some expanded term called expansion.

In mathematics, all real-life problems can be converted into equations which are sometimes in form of factors and we need to expand them to create solutions.

Given that

⇒ 4m(3n-2t)+3t(3t-2m)​

⇒  12mn -8mt + 9t² - 6mt

⇒  12mn + 9t² + 14 mt

Hence it's clear that the coefficient of mt will be -14.

For more information about the expansion

https://brainly.com/question/14447197

#SPJ2

Answer:

2x+3x=180°

that is 5x=180°meaning x=32°

[tex]we conclude that option B:[/tex]

[tex]y + 5 = -\frac{1}{2}*(x - 3)^2[/tex]

[tex]Is the graphed function.[/tex]

On the graph we can see a parabola that opens downwards, so it has a negative leading coefficient.

We also can see that the vertex of the parabola is on the point (3, -5)

Then the equation of the parabola is something like:

y + 5 = a*(x - 3)^2

Where a is a negative real number.

The only option of this form is option B, so we conclude that option B:

[tex]y + 5 = -\frac{1}{2}*(x - 3)^2[/tex]

Is the graphed function.

If you want to learn more about parabolas:

https://brainly.com/question/4061870

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Answer:

[tex]{ \sf{ {(x - 2)}^{2} + {(y + 8)}^{2} = 4}}[/tex]

Answer:

Center is (2, -8) and radius =2

h = 2 and k = -8

Filling in this equation:

(x -h)² + (y -k)² = radius²  we get:

(x - 2)^2 + (y--8)^2 = 2^2 which equals

(x-2)^2 + (y +8)^2 = 4

Source: http://www.1728.org/circleqn.htm

Step-by-step explanation:

Answer:

Arithmetic sequence

Step-by-step explanation:

An list of numbers whereby the difference between each consecutive number is constant is called an arithmetic sequence. Given thelistvif numbers:

–8, –4, 0, 4, 8, 12 ;

We can see that each consecutive number in the list has a constant difference of 4. Hence x this is called an arithmetic sequence.

Answer:

Hello,

Step-by-step explanation:

Since for all real x, f(x)=-f(x),

the function is odd.

Answer:

Solution given:

Right angled triangle ABC is drawn where <C=[tex]\theta[/tex]

we know that

[tex]\displaystyle Sin\theta=\frac{opposite}{hypotenuse} =\frac{AB}{AC}[/tex]

[tex]\displaystyle Cos\theta=\frac{adjacent}{hypotenuse}=\frac{BC}{AC} [/tex]

Now

left hand side

[tex] \displaystyle {sin}^{2} \theta + {cos}^{2} \:\theta[/tex]

Substituting value

[tex](\frac{AB}{AC})²+(\frac{BC}{AC})²[/tex]

distributing power

[tex]\frac{AB²}{AC²}+\frac{BC²}{AC²}[/tex]

Taking L.C.M

[tex]\displaystyle \frac{AB²+BC²}{AC²}[/tex]....[I]

In ∆ABC By using Pythagoras law we get

[tex]\boxed{\green{\bold{Opposite²+adjacent²=hypotenuse²}}}[/tex]

AB²+BC²=AC²

Substituting value of AB²+BC² in equation [I]

we get

[tex]\displaystyle \frac{AC²}{AC²}[/tex]

=1

Right hand side

Answer:

see below

Step-by-step explanation:

Since this is a right triangle, we can use trig functions

cos theta = adj / hypotenuse

cos x = 13/20

Taking the inverse cos of each side

arccos ( cos x ) = arccos( 13/20)

x = arccos ( 13/20)

x =49.45839

x = 49  to the nearest whole number

sin theta = opp/ hyp

sin y = 13/20

Taking the inverse sin of each side

arcsin ( sin y ) = arcsin( 13/20)

y = arcsin ( 13/20)

y=40.5416

y = 41 to the nearest whole number

Answer:

The overall range is 20

Step-by-step explanation:

Given

The above dataset

Required

The overall range

Range is calculated as

[tex]Range = Highest - Lowest[/tex]

The highest of the dataset is 22, and it can be found in  Milkweed.

The lowest of the dataset is 2, and it can be found in  Daisy

So, the range is:

[tex]Range = 22 - 2[/tex]

[tex]Range = 20[/tex]

9514 1404 393

Answer:

  5/3 meters

Step-by-step explanation:

The area is the square of the side length, so the side length is the square root of the area.

  s = √(225/81) = 15/9 = 5/3 . . . meters

The length of a side of the table is 5/3 meters.

Answer:

D

Step-by-step explanation:

The equation of a line in standard form is

Ax + By = C ( A is a positive integer and B, C are integers

12 = 2x + 4y , that is

2x + 4y = 12 ← is in standard form

Step-by-step explanation:

Draw diagonal AC

The triangle ABC has sides 17 and 25

Say AB is 17, BC is 25

Draw altitude on side BC from A , say h

h = 17 sin B

Area = 25*17 sin B = 408

sin B = 24/25

In ∆ ABC

Cos B = +- 7/25

= 625 + 289 — b^2 / 2*25*17

b^2 = 914 — 14*17 = 676

b = 26

h = 17*24/25 = 408/25 = 16.32

Draw the second diagonal BD

In ∆ BCD, draw altitude from D, say DE =h

BD^2 = h^2 + {(25 + sqrt (289 -h^2) }^2

BD^2 = 16.32^2 + (25 + 4.76)^2

= 885.6576 + 266.3424

BD = √ 1152 = 33.94 m

Answer:

5ba^2 +ab^2 6a^2 + 2b

Step-by-step explanation:

ab(6a+b)-3a^2 (b-2)+2b(a^2 +1)

6ba^2 +ab^2 -3ba^2 +6a^2 + 2ba^2 +2b

6ba^2 -3ba^2 +2ba^2 +ab^2 +6a^2 +2b

5ba^2 +ab^2 6a^2 + 2b

Answer:

x=12

Step-by-step explanation:

Since the polygons are similar, we can write a ratio to solve

red side / yellow side

4      2

--- = ---

x       6

Using cross products

4*6 = 2x

24 = 2x

Divide by 2

24/2 =2x/2

12=x

Answer:

12

Step-by-step explanation:

When two shapes are similar, you need to find the scale factor of two existing corresponding sides.

For example, you can do 6 and 2.

Divide:

6/2 = 3

The scale factor: 3

Now multiply 4 and the scale factor (3):

4 × 3 = 12

So, x = 12.

Hope this helped.

Answer:

100km

Step-by-step explanation:

Time taken to travel to Bangi:

x/80 hours

15min = 1/4hrs

Time taken to travel back:

x/80 - 1/4

x= x/(x/80-1/4)

x^2-100x=0

x(x-100)=0

x=0 (rejected) or x=100

Answer:

B. 100km

Step-by-step explanation:

Brainliest please

Answer:

10

Step-by-step explanation:

1x2x2.5=5

5/0.5=10

Answer:

= 40 cubes

Step-by-step explanation:

volume = 2.5×2×1 = 5cm^2

volume of cubes = 0.5×0.5×0.5 = 0.125cm^2

5÷0.125 = 40

= 40 cubes

Answer:

6.25

Step-by-step explanation:

[tex](-2\frac{1}{2})^2\\\\(-\frac{5}{2} )^2\\\\(\frac{5}{2})^2\\\\\frac{5^2}{2^2}\\\\\frac{25}{4}\\\\\boxed{6\frac{1}{4}}\text{ or } 6.25[/tex]

Hope this helps.

Answer:

75 degrees

Step-by-step explanation:

Use trigonometry

we are given opposite(27) and hypotenuse(28), so use sin

sin=opp/hyp

sin(x)=27/28

x=arcsin(27/28)

x=74.64111442

Answer:

4. 12√3

5. -35√2

6. 5√2/2

Step-by-step explanation:

4. 3√12+2√27

= 3√(4×3) + 2√(9×3)

= 6√3+6√3

= 12√3

5. 5√8-9√50

= 5×2√2-9×5√2

= 10√2-45√2

= -35√2

6. 5/√2

= 5×√2/(√2×√2)

= 5√2/2

Answered by GAUTHMATH