Answer:
Step-by-step explanation:For what values of does the equation (2 + 1) have two 2
+ 2 = 10 − 6
real and equal roots?
A quadratic equation that has 2 roots that are equal means that the discriminant of the equation is 0. The value of k that makes the equation have 2 real and equal roots is [tex]k = \frac{5}{6}[/tex]
Given that:
[tex](2k + 1)x^2 + 2x = 10x - 6[/tex]
Rewrite as:
[tex](2k + 1)x^2 + 2x - 10x + 6 = 0[/tex]
[tex](2k + 1)x^2 - 8x + 6 = 0[/tex]
A quadratic equation is represented as:
[tex]ax^2 + bx + c = 0[/tex]
By comparison:
[tex]a=2k+1\\ b =-8\\\ c =6[/tex]
If an equation has 2 real and equal roots, then:
[tex]b^2 = 4ac[/tex]
So, we have:
[tex](-8)^2 = 4 \times (2k + 1) \times 6[/tex]
[tex]64 = 4 \times (2k + 1) \times 6[/tex]
Divide by 4
[tex]16 = (2k + 1) \times 6[/tex]
Divide by 6
[tex]\frac{16}{6} = (2k + 1)[/tex]
[tex]\frac{8}{3} = 2k + 1[/tex]
Subtract 2 from both sides
[tex]2k = \frac{8}{3} -1[/tex]
Take LCM
[tex]2k = \frac{8-3}{3}[/tex]
[tex]2k = \frac{5}{3}[/tex]
Divide by 2
[tex]k = \frac{5}{6}[/tex]
Hence, the value of k that makes the equation have 2 real and equal roots is [tex]k = \frac{5}{6}[/tex]
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Solve the following system of equations for x: xy = 6
3y = x - 3
Answer:
B
Step-by-step explanation:
rearrange 3y = x-3 as x=3y+3 sub in for x in xy=6
(3y+3)(y)=6
solve by factoring 3y^2+3y-6=0
3(y-1)(y+2) = 0
y= 1, -2
sub y back in to either equation but for ease xy=6
x(1)=6 = 6
x(-2)=6 = -3
A sports stadium has a capacity of 42,000. On a
particular night, 35,000 spectators attend an event. At
the end of the event, spectators leave the stadium at a rate
of 320 spectators every minute. If m represents the
number of minutes after spectators begin to leave the
stadium, which of the following inequalities describes
the times when there are still spectators in the stadium?
A) 42,000 - 35,000m < 320
B) 35,000 - 320m > 0
C) 35,000 + 320m < 42,000
D) 320m < 87,000
Answer:
B
Step-by-step explanation:
The inequality will be 35000-320m>0
solve 8x=5x+3 pls pls pls
Answer:
x = 1
Step-by-step explanation:
8x = 5x + 3
Subtract 5x from both sides
8x - 5x = 5x - 5x + 3
Simplify
3x = 3
Divide both sides by 3
3x/3 = 3/3
Simplify
x = 1
f (x) = x - 5. Find f'(x) and its domain.
Answer:
C
Step-by-step explanation:
f(x) = √x - 5
domain: [0. ∞)
range: [-5, ∞)
Let y = √x - 5
√x = y+5
x = (y+5)²
Switch x and y:
y = (x+5)²
f⁻¹(x) = (x+5)²
domain of f⁻¹(x) is the range of f(x): [-5,∞)
A new screening test for West Nile Virus is developed for use in the general population. The sensitivity and specificity of the new test are 60% and 70%, respectively. 300 subjects are screened at a clinic during the first year the new test is implemented. (Assume the true prevalence of West Nile Virus among clinic attendees is 10%.), The predictive value of a positive test is:
The predictive value of a positive test is is 0.43.
------------------
This question is solved using the concepts of sensitivity and specificity.
Sensitivity: It is the true negative rate, that is, the proportion of people without the disease that test negative.Specificity: It is the true positive rate, that is, the proportion of people with the disease that test positive.------------------
Sensitivity of 60% means that of the 100 - 10 = 90% of people without the disease, 60% test negative and 100 - 60 = 40% test positive.Specificity of 70% means that of the 10% with the disease, 70% test positive.------------------
The predictive value of a positive test is:
Probability of a positive test, which is 40% of 90% plus 70% of 10%, so:
[tex]p = 0.4\times0.9 + 0.7\times0.1 = 0.43[/tex]
The predictive value of a positive test is is 0.43.
A similar question is given at https://brainly.com/question/22373775
Find the sum of the first 100 terms of the sequence below:
-19, -15, -11, -7, -3, ...
S100
Answer:
17900
Step-by-step explanation:
First term a = -19
common difference d = -15-(-19) = 4
number of terms, n = 100
sum of first 100 terms,
n/2(2a+(n-1)d)
= 100/2(2×(-19)+(100-1)4)
= 50×(-38+99×4)
= 50×358
= 17900
87.5 into fraction pls help I need this Monday
Answer:
[tex]87.5 = \frac{175}{2} = 87 \frac{1}{2} [/tex]
Answer:
7/8 im not 100% sure i could be wrong tho
Sandra has $75 to spend on a new outfit. She finds a
sweater that costs twice as much the skirt. What is the most
the skirt can cost?
Let s represent the cost of the skirt.
Inequality: _____________________
The most the skirt can cost is _____________________.
The skirt = s
The sweater is twice as much so 2s
The total sum has to equal or be less than $75
Inequality = s + 2s <=75
Simplify to 3s <= 75
Most the skirt can cost: solve for s:
3s <= 75
Divide both sides by 3
S <= 25
The most the skirt can cost is $25
Answer:
Inequality: s ≤ 25
Max skirt cost: $25
Step-by-step explanation:
s = skirt cost
x = sweater cost
Since the sweater costs twice as much as the skirt, an equation will look like this:
x = 2s
Since her budget is $75, that means she can spend $75 or less but not more, so another equation will look like this:
x + s ≤ 75
Plug 2s into the bottom equation
2s + s ≤ 75
Add up the terms
3s ≤ 75
Divide both sides by 3, the coefficient, to isolate s, the variable.
3s/3 ≤ 75/3
s ≤ 25
That means she can spend $25 or less on a skirt.
Question 1 of 10
What is the measure of ZXYZ shown in the diagram below?
Y
S
(369
7
Х
1140
Plz help
Answer:
B
Step-by-step explanation:
Secant-secant with vertex outside the circle
1/2(larger-smaller arc)
1/2(114-36)
1/2(78)
39
Solve for d.
d - 5
———- = -1
-3
Answer:
d = 8
Step-by-step explanation:
(d-5)/ -3 = -1
Multiply each side by -3
(d-5)/ -3 *-3 = -1*-3
d-5 = 3
Add 5 to each side
d-5+5 = 3+5
d = 8
Which is an estimate of V75 to the
nearest whole number?
Answer:
9
Step-by-step explanation:
if that v is root symbol
Rabi Sahu fixed the marked price of his radio to make a profit of 30 %. Allowing 15 % discount on the marked price, the radio was sold. What percent profit did he make?
The percent profit that Rabi made will be 10.5%
Let's assume that the price of the house is $100.
Since he fixed the marked price of the good to make a profit of 30%, then the price will be:
= $100 + (30% × $100)
= $100 + $30
= $130
Now, there is a discount of 15%, then the selling price of the good will be:
= $130 - (15% × $130)
= $130 - (0.15 × $130)
= $130 - $19.50
= $110.50
Then, the percentage of profit made will be:
= [($110.50 - $100) / $100] × 100%
= $10.50/$100 × 100%
= 10.5%
In conclusion, the percent profit that he makes is 10.5%.
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Simplify the expression. Express your answer as an improper fraction in simplest form.
Answer:
Step-by-step explanation:
3/40 is the correct answer
Find the value of x
9
7
X
9
Answer:
13.41
Step-by-step explanation:
You are so welcomed
The measure of each of the remaining angles in the right angle triangle is 45 degrees.
To find the measure of the remaining angles in the triangle, we can use the fact that the sum of the angles in any triangle is always 180 degrees. Since we know one angle is 90 degrees, we can find the measure of the other two angles by subtracting 90 from 180.
Let's call the remaining two angles A and B. Thus, we have:
Angle A + Angle B + 90 degrees = 180 degrees.
Rearranging the equation, we get:
Angle A + Angle B = 90 degrees.
Since the two sides of the triangle adjacent to the right angle are equal (given as 9 and 9), we can conclude that the remaining two angles are congruent (equal). Let's call the measure of each of these angles x.
Therefore, we have:
x + x = 90 degrees.
Simplifying, we get:
2x = 90 degrees.
Dividing both sides by 2, we find:
x = 45 degrees.
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#SPJ2
what is the answer of
445+584-85
Answer:
944 is the correct answer
Answer:
the answer it's 944
445+558=1,029
1,029-85=. [944]✓
Given a sphere with radius r, the formula 4 r2 gives
O A. the volume
O B. the surface area
O c. the radius
O D. the cross-sectional area
Answer: surface area
Step-by-step explanation:
Trên tập hợp số thực cho quan hệ tương đương T như sau: m, n : mTn ⇔ m^3-n^3= m-n . Tìm lớp tương đương của 0 và lớp tương đương của 2021
Answer:
where are u from bro?
Step-by-step explanation:
I didn't understand your language.
name all sets of numbers to which each real number belongs
Answer:
1. Natural Number
2. Integer
3. Rational Number
4. Rational Number
5. Irrational Number
6. Rational Number
7. Rational Number
8. Natural Number
9. Irrational Number
10. Integer
11. Irrational Number
12. Natural Number
In a closed box there are 7 blue balls and 5 red balls. Randomly pick one from the box one at a time until the ball is green, then stop. Find the probability that the person stops after the 4th time
Answer:
1/7 is the probabiltiy
Step-by-step explanation:
Julio is paid 1.1 times his normal hourly rate for each hour he works over 28 hours in a
week. Last week he worked 43 hours and earned $631.90.
Enter and solve an equation to find Julio's normal hourly rate, r. Complete the explanation
how you know that your answer is reasonable.
The earnings equation is $631.90 =
Julio's hourly l'ate is $
per hour.
This is reasonable because working 43 hours at a rate of $14 per hour is
43 · 14 = 43(10 + 4) = 430 + 172 =
and $
is close to $631.90.
Answer:
43-28= 15 extra hours
normal hourly rate = a
extra hourly rate = 1.1a
28a + 15(1.1a) = 631.90
28a + 16.5a = 631.90
How would x^3+8 be expressed in factored form
[tex]\it x^3+8=x^3+2^3=(x+2)(x^2-2x+4)\\ \\ \\ a^3+b^3=(a+b)(a^2-ab+b^2)[/tex]
If f(x) = 4x + 5 and fog(x) = 8x + 13 then find g(x).
Answer:
given
f(x).4x+5
fog(x).8x+13
now
fog(x):8x+13
4x+5(g(x)):: 8x+13
g(x):: 8x+13/4x+5
Answer:
g(x) = 2x + 2
Step-by-step explanation:
One is given the following information:
f(x) = 4x + 5f o g (x) = 8x + 13One is asked to find the following:
g(x)Remember, (f o g (x)) is another way of representing a composite function. A more visual way of representing this composite function is the following (f(g(x)). In essence, one substitutes the function (g(x)) into the function (f(x)) in places of the varaible (x). Thus, represent this in the form of an equation:
f(g(x)) = 8x + 13
Substitute the given infromation into the equation:
4(g(x)) + 5 = 8x + 13
Solve for (g(x)) in terms of (x). Remember to treat (g(x)) as a single parameter:
4(g(x)) + 5 = 8x + 13
Inverse operations,
4(g(x)) + 5 = 8x + 13
4(g(x)) = 8x + 8
g(x) = (8x + 8) ÷ 4
g(x) = 2x + 2
If a ants can dig b tunnels in c hours, how many tunnels can b ants dig in a hours?
9514 1404 393
Answer:
b²/c tunnels
Step-by-step explanation:
The number of tunnels per ant-hour is ...
b/(ac)
Multiplying that by the new number of ant-hours, we have ...
(b/(ac))(ab) = b²/c . . . . tunnels
Can someone please help me? Please C: And thanks!
How much would you need to deposit in an account each month in order to have $50,000 in the account in 8 years? Assume the account earns 4% annual interest compounded monthly.
Answer:
$540.98
Step-by-step explanation:
future value= $ 50,000
number of deposits (n)= 8*12 = 96
rate (r) = 4% per month
= 4÷12 per annum
= 0.33% p.a
i = 0.33÷100
= 0.0033
We know,
Future value of annuity = P÷i [ (1 + i)^n - 1 ]
$50,000 = P÷ 0.0033 [ ( 1+0.0033)^96 - 1]
$50,000 * 0.0033=P [ (1.0033)^96 - 1 ]
$165 = P*0.305
P = $165÷0.305
P = $ 540.98
Rough::
let x= 1.0033)^96
log x = 96 * log (1.0033)
log x = 0.1156
x = Antilog (0.1156)
= 1.305
1.305 - 1 = 0.305
Find the distance of the point (4,4,−4) from the line r(t)=⟨−1+2t,1+2t,3−3t⟩.
Translate the given point and line together so that you get a new point and a new line that passes through the origin. This turns the problem into finding the distance between the new point,
p = (4, 4, -4) - (-1, 1, 3) = (5, 3, -7)
and the new line,
r*(t) = r(t) - ⟨-1, 1, 3⟩ = ⟨2t, 2t, -3t⟩
Let p = ⟨5, 3, -7⟩, the vector starting at the origin and pointing to p. Then the quantity ||p - r*(t)|| is the distance from the point p to the line r*(t).
Let u be such that ||p - r*(t)|| is minimized. At the value t = u, the vector p - r*(t) is orthogonal to the line r*(t), so that
(p - r*(u) ) • r*(u) = 0
I've attached a sketch with all these elements in case this description is confusing. (The red dashed line is meant to be perpendicular to r*(t).)
Solve this equation for u :
p • r*(u) - r*(u) • r*(u) = 0
p • r*(u) = r*(u) • r*(u)
and x • x = ||x||² for any vector x, so
p • r*(u) = ||r*(u)||²
⟨5, 3, -7⟩ • ⟨2u, 2u, -3u⟩ = (2u)² + (2u)² + (-3u)²
10u + 6u + 21u = 4u ² + 4u ² + 9u ²
17u ² - 37u = 0
u (17u - 37) = 0
==> u = 0 or u = 37/17
We ignore u = 0, since the dot product of any vector with the zero vector is 0.
Then the minimum distance distance between the given point and line is
||p - r*(u)|| = ||⟨5, 3, -7⟩ - 37/17 ⟨2, 2, -3⟩|| = √(42/17)
Find theta to the nearest tenth of a degree, if theta is between 0 degrees and 360 degrees for sin theta = 0.4649 with theta in quadrant 2
9514 1404 393
Answer:
152.3°
Step-by-step explanation:
The arcsine function only gives angles in quadrants I and IV. Since this is a quadrant II angle, its value will be ...
θ = 180° -arcsin(0.4649) = 180° -27.7°
θ = 152.3°
Maximum and minimum value
Answer:
Maximum: 1
Minimum: -1
Step-by-step explanation:
To solve this, we can find the derivative of the function and then solve for when the derivative is equal to 0, finding the local maximum and minimum values in this function. Then, we can compare those points to the endpoints of the interval to find the maximum and minimum.
Using the Quotient Rule, we can say that
(f/g) ' = (f'g - fg')/(g²)
[tex]\frac{2x}{x^2+1}dx = \frac{\frac{d}{dx}(2x) * (x^2+1) - \frac{d}{dx} (x^2+1) * (2x) }{(x^2+1)^2} \\= \frac{2 *(x^2+1) - (2x)*(2x)}{(x^2+1)^2} \\[/tex]
Since we just need to solve for 0, we can disregard for the bottom part, resulting in
2(x²+1)-(2x)(2x) = 0
2x²+2-4x² = 0
2-2x² = 0
add 2x² to both sides to isolate the x² and its coefficient
2x² = 2
divide both sides by 2
x²=1
x = ±1
Therefore, we have 4 possible values for the maximum and minimum over this interval:
-2, -1, 0, 1
Trying each of these numbers into f(x),
f(-2) = -4/5
f(-1) = -2/2 = -1
f(0) = 0/1 = 0
f(1) = 2/2 = 1
Therefore, the maximum and minimum values of the function over the given interval are 1 and -1 respectively
Explain why this quadrilateral is not a parallelogram.
Answer:
because only two of it's sides are parallel
Answer:
In this quadrilateral, opposite sides are not parallel. So, this quadrilateral is not a parallelogram.
Step-by-step explanation:
In Parallelogram, opposite sides are parallel
What is the prime factorization of 75
Step-by-step explanation:
The prime fractorization of 75 is 3×5×5 or 3×52
if sin150=1/2 then find sin75
Sin75° = Sin(30° + 45°)
= Sin30°.Cos45° + Sin45°.Cos30°
= 1/2 . √2/2 + √2/2.√3/2
= √2/2 ( 1/2 + √3/2 )
= √2/2 ((1+√3 ) /2 )
= (√2 + √6 )/ 4
