Ok....we have this
924 = 4 ( x + 1) (x + 11) divide both sides by 4
231 = (x + 1) (x + 11) simplify
231 = x^2 + 12x + 11 subtract 231 from both sides
x^2 + 12x - 220 = 0 factor as
(x + 22) ( x - 10) = 0
Set both factors to 0 and solve for x and we get that
x = -22 (reject) or x = 10 (accept)
Dimensions of cuboid are
4, (10 +1), (10 + 11) =
4, 11, 21