The length of a rectangle is 4 inches less than twice its width. If the area of the rectangle is 70 square inches, what are its demensions

By definition, the area of a rectangle is given by:
 A = w * l
 Where,
 w: width
 l: long
 Substituting values we have:
 70 = w * (2w-4)
 Rewriting we have:
 70 = 2w ^ 2-4w
 2w ^ 2 - 4w - 70 = 0
 Solving the polynomial we have:
 w1 = -5
 w2 = 7
 We take the positive root because it is a dimension.
 w = 7 inches
 Then, the length will be:
 l = 2w-4
 l = 2 (7) -4
 l = 14-4
 l = 10 inches
 Answer:
 its demensions are:
 w = 7 inches
 l = 10 inches