Answer:

Step-by-step explanation:
Remove the parentheses and take out the constansts.

Simplify 7 x 3 to 21.

Use the product rule: 

Simplify 2+5 to 7.

Simplfiy 3 + 8 to 11.

Answer:
I believe the cost would be $680
Step-by-step explanation:
Xa+xb+21+2b is the answer