若m-n=4,mn=-1,求(-2mn+2m+3n)-(3mn+2n-2m)-(m+4n+mn)的值谁帮我坐下,

来源:学生作业帮助网 编辑:六六作业网 时间:2024/11/05 17:30:21
若m-n=4,mn=-1,求(-2mn+2m+3n)-(3mn+2n-2m)-(m+4n+mn)的值谁帮我坐下,若m-n=4,mn=-1,求(-2mn+2m+3n)-(3mn+2n-2m)-(m+4n

若m-n=4,mn=-1,求(-2mn+2m+3n)-(3mn+2n-2m)-(m+4n+mn)的值谁帮我坐下,
若m-n=4,mn=-1,求(-2mn+2m+3n)-(3mn+2n-2m)-(m+4n+mn)的值
谁帮我坐下,

若m-n=4,mn=-1,求(-2mn+2m+3n)-(3mn+2n-2m)-(m+4n+mn)的值谁帮我坐下,
(-2mn+2m+3n)-(3mn+2n-2m)-(m+4n+mn)
=-2mn+2m+3n-3mn-2n+2m-m-4n-mn
=(-2mn-3mn-mn)+(2m+2m-m)+(3n-2n-4n)
=-6mn+3m-3n
=-6mn+3(m-n)
将m-n=4,mn=-1代入
=-6mn+3(m-n)
=-6×(-1)+3×4
=-6+7
=1

(-2mn+2m+3n)-(3mn+2n-2m)-(m+4n+mn)
=-2mn+2m+3n-3mn-2n+2m-m-4n-mn
=-6mn+3m-3n=-6*(-1)+3(4)=6+12=18