Me

the question has 7 marks so give 7 valid reasons

Its a cube with dimensions 4 by "x+1" by "x+11"
So if you multiply all 3 of these you will get the total volume of 924.
So our equation is:
4(x+1)(x+11) = 924
(x+1)(x+11) = 231
x²+12x+11 = 231
x²+12x-220 = 0

Now factor to:
(x+22)(x-10) = 0
Thus x = -22 or 10.

Only 10 makes sense here since we can't have a negative length.  So x = 10.
Now plug in x back into our original expressions to get the dimensions.

The original dimesions are: 4cm x 11cm x 21cm

Ta-dah!

It’s going to be d. 4x^2-4x-19’