The length of a rectangle is 3 ft less than twice the width, and the area of the rectangle is 14 ft2 . find the dimensions of the rectangle.

Given: A= 14 ft²  and  l= 2w-3 
formula for area of a rectangle is A=lw
substitute for what you know and simplify: 
14=(2w-3)w -> w= either -2 or 7/2 but because a width value can not be negative you can eliminate the -2 value. w=7/2 
subsitute width into equation for length and solve
l=2w-3= 2(7/2)-3= 4
width: 3.5 ft
length: 4 ft