1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
erastovalidia [21]
2 years ago
8

Write the quadric equation in standard form and then choose the value of "b" (2x-1) (x+5)=0

Mathematics
1 answer:
ASHA 777 [7]2 years ago
6 0

Answer:

2x² + 9x - 5 = 0

b = 9

Step-by-step explanation:

(2x - 1) (x + 5) = 0

Expand

2x² + 10x - x - 5 = 0

Simplify

2x² + 9x - 5 = 0

b = 9

You might be interested in
Complete the squar3
cricket20 [7]

9514 1404 393

Answer:

  1. 4
  2. -2
  3. 4
  4. 2
  5. -2±√2

Step-by-step explanation:

In order to fill the first blank, we need to look at the second line to see what the coefficient of x is.

  1. x² +<u> </u><u>4 </u>x +2 = 0

The constant is subtracted from both sides to get the second line.

  2. x² +4x = <u> -2 </u>

The value that is added on the third line is the square of half the x-coefficient: (4/2)² = 4

  3. x² +4x +<u> 4 </u> = -2 +4

On the fourth line, the left side is written as a square, and the right side is simplified. The square root is taken of both sides.

  4. √(x +2)² = ±√<u> 2 </u>

Finally, 2 is subtracted from both sides to find the values of x.

  5. x = <u> -2 ±√2 </u>

8 0
2 years ago
The heights of a random sample of 50 college students showed a mean of 174.5 centimeters and a standard deviation of 6.9 centime
Minchanka [31]

Answer:

Step-by-step explanation:

Hello!

For me, the first step to any statistics exercise is to determine what is the variable of interest and it's distribution.

In this example the variable is:

X: height of a college student. (cm)

There is no information about the variable distribution. To estimate the population mean you need a variable with at least a normal distribution since the mean is a parameter of it.

The option you have is to apply the Central Limit Theorem.

The central limit theorem states that if you have a population with probability function f(X;μ,δ²) from which a random sample of size n is selected. Then the distribution of the sample mean tends to the normal distribution with mean μ and variance δ²/n when the sample size tends to infinity.

As a rule, a sample of size greater than or equal to 30 is considered sufficient to apply the theorem and use the approximation.

The sample size in this exercise is n=50 so we can apply the theorem and approximate the distribution of the sample mean to normal:

X[bar]~~N(μ;σ2/n)

Thanks to this approximation you can use an approximation of the standard normal to calculate the confidence interval:

98% CI

1 - α: 0.98

⇒α: 0.02

α/2: 0.01

Z_{1-\alpha /2}= Z_{1-0.01}= Z_{0.99} =2.334

X[bar] ± Z_{1-\alpha /2} * \frac{S}{\sqrt{n} }

174.5 ± 2.334* \frac{6.9}{\sqrt{50} }

[172.22; 176.78]

With a confidence level of 98%, you'd expect that the true average height of college students will be contained in the interval [172.22; 176.78].

I hope it helps!

4 0
2 years ago
Variable y varies directly with variable x, and y = 5 when x = 8.
qaws [65]
Y = kx

Plug in what we know:

5 = k(8)

5 = 8k

Divide 8 to both sides:

k = 0.625

Plug this back into the equation along with y = 15:

y = kx

15 = 0.625x

Divide 0.625 to both sides:

x = 24
4 0
3 years ago
Read 2 more answers
there is a traffic light at the intersection of Pine Street and Spruce Avenue. The traffic light on Pine Street follows a cycle.
Alex17521 [72]
The propability is the least chance because it is the lowest time frame that it is on for


8 0
2 years ago
100 points and brainliest for correct answer!
MatroZZZ [7]
Answer B.

∑fx=1637,∑fx
2
=127663,∑f=21
x
ˉ
=Mean=
∑t
∑fx
​
=77.95
σ
2
=
∑f
∑fx
2

​
−(
x
ˉ
)
2
=
21
127663
​
−(77.95)
2
=2.987
σ=1.728
4 0
2 years ago
Other questions:
  • How do you write the number 7 × 10-2 in standard form?<br> a. 7<br> b. 0.0007<br> c. 700<br> d. 0.07
    5·1 answer
  • What is the value of 4 in the number 745
    15·2 answers
  • Hannah and Francine have $120. Hannah and Peter have $230. Peter has 6 times as much money as Francine. How much money does Hann
    10·1 answer
  • What should be done first to simplify 18 - 3 + 5 + 2 - 13 + 12
    7·1 answer
  • How to simplify this problem?
    15·1 answer
  • (-2a cubed b squared)(3a to the forth b to the sixth)
    5·1 answer
  • Assume that when adults with smartphones are randomly​ selected, ​57% use them in meetings or classes. If 8 adult smartphone use
    14·1 answer
  • Need help with this equation
    15·1 answer
  • Gabriela believes that purchasing the sound system is an essential purchase . Does that mean buying a sound system is an essenti
    10·1 answer
  • What is the next fraction in this sequence? Simplify your answer.<br> 1 1 1 5<br> 6,4, 3, 12,
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!