7th grade math
posted by Delilah .
Simplify each expression.
1.
2z  3y  8z + y
2.
9  7t + 1 + 4t
3. For the summer, Tia buys 3 Tshirts and 2 pairs of shorts. Her brother buys 4 Tshirts and 1 pair of shorts. Define and use variables to represent the total cost.
I have no idea how to do this! Please help!

1.
2z  3y  8z + y
Combine like terms:
2z  8z  3y + y
6z  2y
Do the second problem the same way.
3. This problem isn't clear. Do we assume that all Tshirts cost the same? Do all shorts cost the same? Please clarify. You may need to ask your teacher about this one. 
so is:
#2.
10  3t 
Yay! You're right! :)