Question 1001688
Hi there,
Make the width = 'x'
Length = 4x - 5
Perimeter of rectangle 
= 2(width) + 2(length)
100 = 2(x) + 2(4x - 5)
100 = 2x + 8x - 10
Collect like terms.
10x = 100 + 10
10x = 110
x = 11
Width = 11 inches
Length = 39 inches
Hope this helps :-)