【 】÷【mn】=2m-3n

【 】÷【mn】=2m-3n 急2[mn+(-3m)]-3(2n-mn),m+n=2 mn=-3 1/M+1/N=5 (3M+MN+2N) / (M-MN=3N) 已知m-n=2,mn=1,求多项式(-2mn+2mn+3n)-(3mn+2n-2m)-(m+4n+mn)的值 已知m-n=2,mn=1,求多项式(-2mn+2mn+3n)-(3mn+2n-2m)-(m+4n+mn)的值 已知m+n=3,mn=2/3,求mn-mn+mn的值 m+n=3,mn=-2时,2(-mn+3n+4m)—(14n+18m—mn)÷2的值 已知mn/m+n=2求3m-5mn+3n/-m+3mn-n 已知M+N分之MN=2,求-m+3mn-n分之3m-5mn+3n 已知mn/m+n=2,求3m-5mn+3n/（-m）+3mn-n 已知mn／m+n=2,求3m-5mn+3n/-m+3mn-n的值 m-n=7 mn=-5求(3m+5n+4mn)-(2n-4n+6mn) 已知m-n=4,mn=2,求多项式（-2mn+2m+3n)-(3mn+2n-2n)-(m+4n+mn)的值 已 知m-n=4,mn=-1,求：（-2mn+2m+3n)-(3mn+2n-2n)-(m+4n+mn)的值 已知m-n=3,mn=-3,求(-m-4n-mn)-(2mn-2m-3n)-(3mn+2n-2m)的值 已知m-n=3,mn=-1,求多项式-2mn+2m+3n-3mn-2n+2m-4n-m-mn的值 已知m-n=2,mn=1,求多项式(2mn+2m+3n)-(3mn+2n-2m)-(m+4n+mn)的值 已知m-n=4,mn=2,求多项式（-2mn+2m+3n)-(3mn+2n-2m)-(m+4n+mn)的值.