Question 1053709
Let w be the width of the box. Then the length would be w+3. So:
4w(w+3)=160
4w²+12w-160=0
w²+3w-40=0
(w+8)(w-5)=0
w=5 or -8
Throwing out the negative result, we get the length and width of the box to be 8 and 5, respectively. ☺☺☺☺