Answer:
(n-7) (n+6)
Step-by-step explanation:
1. You need to find two numbers that's product will equal to 42 and it's sum is -1.
2. You could probably figure out it's 7 & 6 by now and now you have to figure out which one is positive or negative since they both can't be positive or negative since the product needs to be negative and if it will come out to -1. It's simple math from -7 + 6 equals -1. So the 7 would be negative in the equation and the 6 would be positive.
You can use the Pythagorean theorem to answer this. The diagonal is the hypotenuse of the right triangle that is formed. So, your equation will look like (h is height):

We have to solve for h:


You can plug it into a calculator, and you get approximately 19.105. The answer closest to that is
B. So, that's your answer! Hope it helps. If anything doesn't make sense, hmu!
Answer:
78.88%
Step-by-step explanation:
We have been given that

The z-score formula is given by

For 

For 

Now, we find the corresponding probability from the standard z score table.
For the z score -1.25, we have the probability 0.1056
For the z score 1.25, we have the probability 0.8944
Therefore, the percent of the trees that are between 20 and 30 years old is given by
0.8944 - 0.1056
= 0.7888
=78.88%