2x4=8 2x2=4 4+8=12, so it is A
The formula of a volume of a cuboid:

l - length
w - width
h - height
We have:
l = (x + 4) cm
w = (x + 1) cm
h = 3 cm
Substitute:
<em>use distributive property</em>


<em>combine like terms</em>

Eat!! Sleep!! and do what ever they want!!
or they just build a house