B) Find the length I where the area A=72 square inches and the width
w=8 inches.

L = 9

Step-by-step explanation:

A = L x W

72 = L x 8

72/8 = L

9 = L

The length is 9 in

Step-by-step explanation:

This figure sounds like a rectangle of area 72 in^2, width 8 in and length l.

The appropriate formula is A = (l)(w) = (length)(width).

Here we know that the area is 72 in^2 and the width is 8 in.  

The most efficient way to calculate the length, l, is to solve the above formula  for (l) and then substitute the values for A and w:

            A

(l) =

            w

                  72 in^2

Here,  (l) = = 9 in

                    8 in

The length is 9 in

use this formula:

p(a\b) = p(a and b)/p(b).

take it from here.