Answer: D. Increased by 14
Explanation:
We can create an example situation to help us visualize this problem.
The equation for a rectangle's perimeter can be found with P = 2L + 2W. Let us say that the L is 2 and the W is 3.
P = 2L + 2W
P = 2(2) + 2(3)
P = 10
Now, in our example situation, we will increase the length by 7. Now it is 9.
P = 2L + 2W
P = 2(9) + 2(3)
P = 24
Our perimeter increased by 14 (24 - 10 = 14), giving us option D as our answer.
This is because the formula multiplies this increase by 2, meaning that the end result is increased by 14 (since 7 * 2 = 14).