This is hard to understand , do u have a photo
Answer:

Step-by-step explanation:

There are 3 nickels because if you use the ratio 6 to 1 you multiply 6 by 3 to get 18 pennies and you do the same with the one and that’s how I got 3 nickels.
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 :)