(m^2-6mn+9n^2)/(3n-m)-(4m^2-9n^2)/(2m-3n) m=-2 n=2008.化简求值

m-n=7 mn=-5求(3m+5n+4mn)-(2n-4n+6mn) 若m-n=4,mn=-1求(9-2mn+2m+3n)-(3mn+2n-2m)-(m+4n+mn) 先化简再求值,3m^2-mn/9m^2-6mn+n^2其中m=3n 计算:[-m^3n/(m-n)^2]^4*[(n^2-mn)/m]^3/m^4n^10*[(mn-n^2)/m]^6 1/M+1/N=5 (3M+MN+2N) / (M-MN=3N) (5mn-2m+3n)+(-7m-7mn) (5mn-2m+3n)+(-7m-7mn) 已知MN^2=-6,求-MN(M^2N^5-MN^3-N)的值 已知m-n=2 则3m^2-6mn+3n^2-9= 计算(2m-3n)(4m^2+6mn+9n^2) 分解因式；9m^2+6mn-3m-n+n^2 (m^2-6mn+9n^2)÷(m-3n)-(4m^2-9n^2)÷(2m-3n),其中m=-3,n=-1/3(m^2-6mn+9n^2)÷(m-3n)-(4m^2-9n^2)÷(2m-3n),其中m=-3,n=-1/3 m^3n-2m^2n^2+mn^3 m²-3mn+2n²+m-n因式分解 因式分解：8mn(n-m)+2(n-m)^3 因式分解：8mn(n-m)+2(n-m)^3, 若(m+n)^2-mn(m+n)=(m+n)·M,则M是（） A.m^2+n^2 B.m^2-mn+n^2 C.m^2-3mn+n^2 D.m^2+mn+n^2 (m-n)(m^5+m^4n+m^3n^2+m²n^3+mn^4+n^5)