1 it grows 18 inches every 3 months
there are 12 months in 1 year
12 dived by 3 = 4 so there are 4 times it will grow 18 inches
18 * 4 = 72 inches, amount it grows in 1 year
Answer is D
2. it grows 9 inches every 2 months
12/2 = 6 times a year it will grow
9 *6 = 54 inches total for 1 year
Answer is C
Answer:
Step 2
Step-by-step explanation:
Michelle's step in trying to solve the equation is given below:

Michelle made a mistake in Step 2.
The right hand side of Step 1: 
Rather, the correct sum is:

Side of the square computer screen = 21 inches
It is important to minutely read the details that are already given in the question. the most important information that is given in the question is that the computer screen ia square. Based on this information the answer to the question can be easily deduced.
Then
Area of the computer screen = (Side)^2
= (21)^2 inches square
= 441 inches^2
So the area of the square computer screen is 441 square inches. i hope the procedure is clear enough for you to understand.