Answer:The missing dimensions are now
width =7inches
length = 11 inches
Height = 3 inches
Explanation:
Volume of a box is given as =width x length x height 231 in^3
Given
width = 7 inches
height =represented as h
l = 8 inches more than the height= 8+h
V = w x l x h
231 = 7(8+h)(h)
231=( h² + 8h)7
231/ 7= h²+8h
33= h²+8h
Giving us the quadratic equation
h² + 8h - 33 = 0
=(h-3)(h+11) = 0
h-3= 0
h= 3 also h+11=0, h=-11
h= 3 or -11
Since the value of height cannot have a negative value,
h = 3inch
l = 8+h = 8+3 = 11 in
The missing dimensions are now
width =7inches
length = 11 inches
Height = 3 inches