(-2ab+2a+3b)-(3ab+2b-2a)-(a+4b+ab)=-2ab+2a+3b-3ab-2b+2a-a-4b-ab=-6ab+3a-3b=-6ab+3(a-b)将a-b=4,ab=1代入上式原式=-6*1+3*4=-6+12=6所以(-2ab+2a+3b)-(3ab+2b-2a)-(a+4b+ab)=6
解:将欲求式展开并整理得到-6ab+3a-3b =-6ab+3(a-b) 将已知a-b=4,ab=1代入上式,即得-6X1+3X4=6。
先打开括号-2ab+2a+3b-3ab-2b+2a-a-4b-ab-6ab+3a-3b将ab=1代入-6+3a-3b-6+3(a-b)将a-b=4代入-6+12=6
先化建.自己算啊.