could you explain a bit more?
If you would like to solve 75% of x peaches is 15 peaches, you can calculate this using the following steps:
75% of x peaches is 15 peaches
75% * x = 15
75/100 * x = 15 /*100/75
x = 15 * 100 / 75
x = 20 peaches
Result: 75% of 20 peaches is 15 peaches.
Multiply both sides by a
az=ab+m
Subtract ab from both sides
az-ab=m
pull a from az-ab
a(z-b)=m
Divide both sides by z-b
a=m/z-b