Question 607284
width = W
the length of a rectangle is 3 inches longer than the width:
length = 3 + W
perimeter of the rectangle is 78:
perimeter = 2*(length + width)
78 = 2*(3 + W + W)
78 = 2*(3 + 2W)
78 = 6 + 4W -> this is the equation


the solution will be:
78 - 6 = 4W
72 = 4W
W = 72/4 = 18
length = 3 + W = 3 + 18 = 21
so, the length of the rectangle is 21 inches and the width is 18 inches