已知m-n=5,mn=-3,求-(m+4n-mn)-(2mn-2m-3n)+(2n-2m-3mn)的值.

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已知m-n=5,mn=-3,求-(m+4n-mn)-(2mn-2m-3n)+(2n-2m-3mn)的值.已知m-n=5,mn=-3,求-(m+4n-mn)-(2mn-2m-3n)+(2n-2m-3mn

已知m-n=5,mn=-3,求-(m+4n-mn)-(2mn-2m-3n)+(2n-2m-3mn)的值.
已知m-n=5,mn=-3,求-(m+4n-mn)-(2mn-2m-3n)+(2n-2m-3mn)的值.

已知m-n=5,mn=-3,求-(m+4n-mn)-(2mn-2m-3n)+(2n-2m-3mn)的值.
-(m+4n-mn)-(2mn-2m-3n)+(2n-2m-3mn)
=-m-4n+mn-2mn+2m+3n+2n-2m-3mn
=-m+n-4mn
=-(m-n)-4*mn
=-5-4*(-3)
=7

原式=-m-4n+mn-2mn+2m+3n+2n-2m-3mn
=-m+n-4mn
=-(m-n)-4mn
=-5+12
=7