You can perform all kind of operation that are one the inverse of the other, so that the value won't change. For example, you can multiply and divide by 2:

Or add and subtract 5:

Answer:
d
Step-by-step explanation:
XYR=36 hope this helps I actually don't know if it is right so I'm so sry if it is wrong so sry
Most likely 10 because the initial amount is 5