HELP WILL MARK BRAINLIEST FOR CORRECT.

Find an integer value of b that makes x^2 + bx - 81 factorable.

Kaylis [27]

Answer:

b = 80

Step-by-step explanation:

Given that,

x² + bx - 81

To find,

value of b

What is factorable?

A polynomial equation with highest degree 2 is if factorable when

we can find two terms which when multiples = -81x², ( x² * - 81 = -81x² )
and when add = bx

possible factors:

-1x * 81x = -81x² (Accepted)
1x * -81x= -81x² (rejected)
9x * -9x = -81x² (rejected)
-9x * 9x = -81x² (rejected)

Only when -1x , 81x is added -1x + 81x = 80x

so, bx = 80x

b = 80

<h3>The equation is x² + 80x - 81</h3>

5 0

3 years ago

Solve 1/2 + (- 3/4) =

Crazy boy [7]

Answer:

-0.25 or 1/4

Step-by-step explanation:

Eh just know

5 0

3 years ago

The price of a DVD is $19 . The price is 12% lower than last week. What was the price of the DVD last week? Round your answer to

nataly862011 [7]

Answer:

The original cost of the DVD was $21`.59

Step-by-step explanation:

In order to find this, you first must note that the new price is 88% of the older price. We get this since there was a subtraction of 12%.

Now knowing that, we can divide the new price by the percentage paid and it will give us the original price.

$19/88% = Original Cost

19/.88 = Original Cost

$21.59 = Original Cost

5 0

3 years ago

A company claims that 5% of its products will be defective. A simple random sample of 300 products contain 10 defective products

Radda [10]

Answer:

wateva

Step-by-step explanation:

wateva u want it too be good luck

3 0

3 years ago

Suppose that the distribution of typing speed in words per minute (wpm) for experienced typists using a new type of split keyboa

KengaRu [80]

Answer:

a. 0.5 or 50%

b. 0.496 or 49.6%

c. 0.8185 or 81.85%

d. Yes, it would be just 0.0013 or 0.13% of probability to find a typist whose speed exceeds 105 wpm

e. 0.0252 or 2.52%

f. The qualifying speed would be 47.4 wpm.

Step-by-step explanation:

a. Let's find the z-score this way:

μ = 60 σ= 15

z-score = (x - μ)/σ

z-score = (60 - 60)/15

z-score = 0

Now, let's calculate the p value for z-score = 0, using the z-table:

p (z=0) = 0.5 or 50%

b. z-score = (x - μ)/σ

z-score = (59.9 - 60)/15

z-score = -0.01

Now, let's calculate the p value for z-score = -.0.01, using the z-table:

p (z = -0.01) = 0.496 or 49.6%

If the question were less or equal than 60, a and b would have the same answer. But in this case, the question is "less than 60 wpm".

c.

z-score = (x - μ)/σ

z-score = (45 - 60)/15

z-score = - 1

Now, let's calculate the p value for z-score = -1, using the z-table:

p (z = -1) = 0.1587

z-score = (x - μ)/σ

z-score = (90 - 60)/15

z-score = 2

Now, let's calculate the p value for z-score = 2, using the z-table:

p (z = 2) = 0.9772

In consequence,

p (-1 ≤ z ≤ 2) = 0.9772 - 0.1587 = 0.8185 or 81.85%

d. z-score = (x - μ)/σ

z-score = (105 - 60)/15

z-score = 3

Now, let's calculate the p value for z-score = 3, using the z-table:

p (z = 3) = 0.9987

In consequence,

p (z > 3) = 1 - 0.9987 = 0.0013

Yes, it would be just a 0.13% of probability to find a typist whose speed exceeds 105 wpm.

e. z-score = (x - μ)/σ

z-score = (75 - 60)/15

z-score = 1

Now, let's calculate the p value for z-score = 1, using the z-table:

p (z = 1) = 0.8413

In consequence,

p (z > 1) = 1 - 0.8413 = 0.1587

and if the two typists are independently selected, then

p = 0.1587 * 0.1587

p = 0.0252 or 2.52%

f. p = 0.2, using the z-table, the z-score is -0.84, then:

z-score = (x - μ)/σ

-0.84 = (x - 60)/15

-12.6 = x - 60

-x = -60 + 12.6

-x = - 47.4

x = 47.4

The qualifying speed would be 47.4 wpm.

8 0

3 years ago