已知m-n=3,mn=-1,求多项式-2mn+2m+3n-3mn-2n+2m-4n-m-mn的值

来源:学生作业帮助网 编辑:作业帮 时间:2024/11/27 13:14:41
已知m-n=3,mn=-1,求多项式-2mn+2m+3n-3mn-2n+2m-4n-m-mn的值
x){}Ksulurlu umlzd˅;56655qtMtsusjyڰ&HrC l| lù*suQ@{5!fږ~qAbԁ6`֎:tB󍻁Ħ N55626

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=3,mn=-1,求多项式-2mn+2m+3n-3mn-2n+2m-4n-m-mn的值

已知m-n=3,mn=-1,求多项式-2mn+2m+3n-3mn-2n+2m-4n-m-mn的值
-2mn+2m+3n-3mn-2n+2m-4n-m-mn
=-6mn+3m-3n
=-6mn+3(m-n)
=6+9
=15

15 先合并同类项

-2mn+2m+3n-3mn-2n+2m-4n-m-mn
=-6mn+3m-3n
=-6mn+3(m-n)
=-6*(-1)+3*3
=6+9
=15