杭州交通信息网福州工厂通道闸厂商:数学题(速求!!!!!!!!!!!!!!!!!!!!!!!!)
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一个整式A减去ab-2bc+3ac,一同学误将减号写成加号,结果是-2ab+bc+8ac.
1.求整式A
2.求正确答案.
(有过程)
1.求整式A
2.求正确答案.
(有过程)
A+[ab-2bc+3ac]=-2ab+bc+8ac
A=-3ab+3bc+5ac
2.正确答案：[-3ab+3bc+5ac]-[ab-2bc+3ac]=-4ab+5bc+2ac
1.A-(ab+2bc+3ac)=-2ab+bc+8ac
A=-ab+2bc+11ac
2.A-(ab-2bc+3ac)
=(-ab+2bc+11ac)-(ab-2bc+3ac)
=-2ab+3bc+8ac
1、A=（-2ab+bc+8ac）-（ab-2bc+3ac）=-3ab+3bc+5ac
2、正确答案：
=-3ab+3bc+5ac-（ab-2bc+3ac）=-4ab+5bc+2ac
(1)A+ab-2bc+3ac=-2ab+bc+8ac
A=-2ab+bc+8ac-(ab-2bc+3ac)
=-3ab+3bc+5ac
(2)A-ab-2bc+3ac
=-3ab+3bc+5ac-(-2ab+bc+8ac)
=-ab+bc-3ac
A+(ab-2bc+3ac)=-2ab+bc+8ac
所以:A=-2ab+bc+8ac-(ab-2bc+3ac)=-3ab+3bc+5ac
1,A+(ab+2bc+3ac)=-2ab+bc+8ac
so,A=-3ab-bc+5ac
2,-ab-bc+6ac-(ab-2bc+3ac)=-2ab+bc+3ac