x^3y^m-1*x^m+n*y^2n+2=x^9y^9,
x^(m+n+3)y^(m+2n+1)=x^9y^9
m+n+3=9
m+2n+1=9
两式相减
n-2=0
n=2
m=6-n=6-2=4
4m-3n=4x4-3x2=10