m^2x-9n^2x-9n^2+m^2y因式分解

(x+y)(m+n)2-(x+y)(m+n)2 m(x-y)^n+n(y-x)^2n因式分解 x^n*y*(-x^2y^m) 已知x^m+n=9,y^m+n=16,求（-三分之一*x^m*y^n)^2*x^2n*y^2n的值? 已知x^m+n=9,y^m+n=16,求（-三分之一*x^m*y^n)^2*x^2n*y^2n的值? m^2x-9n^2x-9n^2+m^2y因式分解 1)x^2-y^2-x+四分之一2)9m^2-n^2+3m-n 已知-7x^m-2n y^4与9分之8x^5 y^m+n 是同类项,求（m-2n)^2 -3(m+n)-5(m-2n)^2 +m+n的值 若x^3y^m-1*x^m+n*y^2n+2=x^9y^9,则4m-3n=（）. 2x^6n-x^4n×y^3m-y^9m,已知x^2n=3,y^3n=2,求值 y^2-9(x+y)^2.a(x-y)-b(y-x)+c(x-y)..x（m+n)-y(n+m)+(m+n)..(x+y)^2-16(x-y)^2因式分解 {2m+9n=48 {3m-5n=-15 求x和y 已知函数f(x)=2/3x²-4x+9,求实数m,n,使x∈[m,n]时,y∈[m,n]. （m+n)x^2+2xy(n-2m)+(4m+n)y^2 2m+n=x 2n+m=y 求m-n的最小值 3x+4y=-5 5x+6y=-9 (n-8m)x-8y=10 5x+(10m+2n)y=-9 求m.m+n.n=? 因式分解：3a(x-y)+9(y-x)(2m-3n)²-2m+3n X^3*y^(m-1)*x^(m+y)*y^(2n+2)=x^9y^9