(x3y-2)2/(x5y3)-3
Remembering that x-a = 1/xa, we can re-write the expression as:
(x3)2(x5y3)3/(y2)2
Now (xa)b = xab:
x6x15y9/y4
Since xaxb = xa+b and xa/xb = xa-b, we can combine terms with the same base and simplify:
x6+15y9-4
x21y5