Eva wants to make 2 pieces of pottery. she needs 3/5 pound of clay for 1 piece and 7/10pound of clay for the other. she has 3 bags of clay that weigh 4/5pound each. how many will bags will eva need to make both pieces? how many pounds will she have left over?

There are two questions that need to be answered here. Let's address the first one here:
How many bags will Eva need to make both pieces?
She needs 13/10 lbs. There are 8/10 lbs per bag. She would use 1 5/10 bags, but since they are bags, you would say 2.
Now, the second question:
How many pounds are left over?
She started with 3x8/10=2.4 lbs
We take away what she used: 2.4-1.5=0.9
There will be 0.9 lbs left over.