Answer:
Length: 11
Width:5
Explanation:
Let's say x is the width, then length is 3x-4
Area of a rectangle is Length times width
so x(3x-4)=55
then we solve
3x^2-4x-55=0
(3x+11)(x-5)=0
x cannot be negative so x=5
then if the width is 5, length is 3*5-4=11