Answer:
x² – x – 12 = (x – 4)(x + 3)
Step-by-step explanation:
Identify two numbers that add to -1 and multiply to -12, let's call them p and q.
So ax² + bx + c = (x + p)(x + q)
pq = c
p + q = b.
It is easier to find these numbers by finding factors of -12.
This can be done by splitting the number up until all the numbers are prime.
-12 → 6 × -2 or -6 × 2 → -(3 × 2 × 2)
There can only be two numbers so the only options we have are 6 and -2, -6 and 2, 3, and -4, or -3 and 4.
We can eliminate them by adding them up.
6 + -2 = 4 ≠ -1 so that can't be it.
-6 + 2 = -4 ≠ -1 so that can't be it either.
-3 + 4 = 1 ≠ -1
therefore p and q are 3 and -4 because 3 + -4 = -1.
so x² – x – 12 = (x – 4)(x + 3)
p = -4, and q = 3.
(x – 4)(x + 3) = x(x + 3) – 4(x + 3) = x² + 3x – 4x + 12 = x² – x – 12
Answer:
<u>B. There is sufficient evidence that the mean of the pressure required to open a certain valve has changed. </u>
Step-by-step explanation:
We make this conclusion based on these reasons:
- We are told that the "null hypothesis was rejected" after the <em>"manager feels that the pressure variability has changed.,</em> meaning the <u>null hypothesis was the opposite of what occurred; that is to say, it is the alternate hypothesis that proved true instead.</u>
- <em>"changes in the manufacturing process"</em> form what can be called "sufficient evidence" that the mean of the pressure required to open the valve has changed, thereby going against the null hypothesis.
It is based on the above reasons that the null hypothesis was rejected.
Number one, is 430 divided by 18. 430/18 = 23.8888889 = rounding the number should make 23.4
D
Substitute the values of x and y