## Algebra 1

Total cost is $200-8c$.
The cost of CDs is $12c$. The cost of DVDs is $200-20c$. total cost=$12c+(200-20c)$ $=12c+(200+(-20c))$ $=200+(12c+(-20c))$ $=200+(-8c)$ $=200-8c$ Use the commutative an associative properties of addition to combine like terms.