问题描述: 已知x+4y=-1,xy=5,求(6xy+7y)+{8x-5xy-y+6x)}的值老师给我讲详细点 1个回答 分类:语文 2015-10-27 问题解答: 我来补答 解题思路: 本题是求整式的值,注意一定要先化简,再求值。化简就是先去括号,在合并同类项。解题过程: 解:(6xy+7y)+[8x-(5xy-y+6x)] =(6xy+7y)+[8x-5xy+y-6x] =6xy+7y+8x-5xy+y-6x =(6-5)xy+(7+1)y+(8-6)x =xy+8y+2x =xy+2(x+4y) =5+2×(-1) =3 答:(6xy+7y)+[8x-(5xy-y+6x)]的值为3. 展开全文阅读