-1 you are correct about that answer
Answer:
B
Step-by-step explanation:
Answer:
900
Step-by-step explanation:
Sum of interior angle for a polygon = (n-2)180
7 sides
=(7-2)180
=5*180
=900
<h2>
Hello!</h2>
The answer is:

<h2>
Why?</h2>
To solve the problem we need to add/subtract like terms. We need to remember that like terms are the terms that share the same variable and the same exponent.
For example, we have:

We have that we were able to add just the terms that were sharing the same variable and exponenr (x for this case).
So, we are given the expression:

Hence, the answer is:

Have a nice day!
So, let's make these two values improper fractions so they're easier to work with. 
So, to get the rate he grew in those months we have:
And to get the rate he grew in one month we have to divide both our numerator and our denominator by 21 to get:
aka he grew 1.24 inches in a month.