7m²n-3mn²+5m²n+2mn²

(7m²-4mn-n²)-(3m²-mn+2n²)求解 (3m-2n)²+24mn 规定新运算：m#n=m+n,m﹡n=m-n,试化简[(mn²﹚#(2mn)]+[(4mn²)﹡(3m 已知m+n+=3,mn=三分之二,求m²+(n-m)²+2m(n-mn)的值 m²n(m-n)-4mn(n-m) 4-m²n²+2mn m-n分之m - m+n分之n + m²-n²分之2mn 化简(m²/m-n - m+n)÷2m²-mn/n - m 先化简,再求值.①（mn-m²)÷m²-2mn+n²/mn·m²-n² 分式2n/m²-mn,m/n²-mn,n/m²-n²的最简公分母 -2(mn-3m²)-[m²-5(mn-m²)+2mn],其中m=1,n=-2 快. 先化简,后求值:-2(mn-3m²)-【m²-5(mn-m²)+2mn】,其中m=1,n=