Answer:
7 inches
Step-by-step explanation:
Area of a rectangle = Length * Width
A = LW ....1
If the length of the rectangle is 4 inches greater than three times its width, then;
L = 3W + 4 ... 2
Substitute equation 2 into 1;
A = (3W+4)W
175 = 3W^2+4W
3W^2+4W-175 = 0
Factorize
3W^2-21W+25W-175 = 0
3W(W-7)+25(W-7) = 0
(3W+25) (W-7) = 0
3W+25 = 0 and W-7 = 0
3W = -25 and W = 7
W = -25/3 and W = 7
Since the width cannot be negative, hence the width of the rectangle is 7inches