if x y is 25 more than x-y then x is what percent of y ?
x * y = x - y + 25 Add y to both sides
x * y + y = x - y + 25 + y
x * y + y = x + 25
y ( x + 1 ) = x + 25 Divide both sides by x + 1
y = ( x + 25 ) / ( x + 1 ) Long Division of Polynomials
y = 1 + 24 / ( x + 1 )
You have infinite numbers of solutions, so you must give one more condition.