You need to simplify it first.

Use distribution

y=mx+b
m=slope
your slope is -4 :)
Answer:
To find the surface area of a prism, find the area of a base and double it since the areas of the two bases are always equal. Then find the area of each side face, and add to the area of the bases. A pyramid has one base and triangular sides.
Step-by-step explanation:
I think that is is 8.3, but I could be incorrect!