12) First multiply 354 by 3.
Since it is a cube, all sides lengths are the same.
Surface area = 2lw+2lw+2hw
if you substitute all the sides for 13 you get
2(169) three times
so you multiply and get 338 three times so you do 338x3 which is 1014 cm
its messy to explain so i attached a photo
If the -8 is under the square root, then...

OR
If the -8 is not under the square root, then...

Either way, we replace x with -3 and simplify.
For more information, refer to the direct substitution rule for limits.