Apizza had 9/10 left before lucas ate 4/5 of the pizza. how much pizza is left over

1/10 is left.

Explanation:

First we need to find a common denominator. Since 5×2=10, if we multiply 4/5 by 2/2, we will be able to subtract that from 9/10.

4/5×2/2= 8/10. Then if we subtract that from the 9/10 left of the pizza, we get 1/10, the amount remaining.

Hope this helps :)