早教吧 育儿知识 作业答案 考试题库 百科 知识分享

1、(x-y)+2(x-y)+(x+y)2、4a-8b-(a-2b)3、(a+2b)+8(a+2b)+164、xy(x+y)-8xy(x+y)+16(x+y)5、(x+y)-2xz-2yz+z6、(x+y)(x+y+2)+17、(x-2x-2)(x-2x+4)+98、(x+y)-4xy

题目详情
1、(x-y)+2(x-y)+(x+y) 2、4a-8b-(a-2b) 3、(a+2b)+8(a+2b)+16 4、xy(x+y)-8xy(x+y)+16(x+y) 5、(x+y)-2xz-2yz+z 6、(x+y)(x+y+2)+1 7、(x-2x-2)(x-2x+4)+9 8、(x+y)-4xy
▼优质解答
答案和解析
1、(x-y)+2(x-y)+(x+y) =x-2xy+y+2x-2y+x+2xy+y =4x 2、4a-8b-(a-2b) =4(a-2b)-(a-2b) ={4-(a-2b)}(a-2b) ={2-(a-2b)}{2+(a-2b)}(a-2b) 3、(a+2b)+8(a+2b)+16 ={(a+2b)+4} 4、xy(x+y)- 8xy(x+y)+16(x+y) =xy(x+y)- 8(x+y)(xy-2) =(x+y){xy - 8(xy-2)} 5、(x+y)-2xz-2yz+z =(x+y)-2(x+y)z+z =(x+y-z) 6、(x+y)(x+y+2)+1这是最简的了 7、(x-2x-2)(x-2x+4)+9 =(x-2x+1-3)(x-2x+1+3)+9 ={(x-1)-3}{(x-1)+3}+9 =(x-1) 4 -9+9 =(x-1) 4 8、(x+y)-4xy =x+y+2xy-2xy-(2xy) =(x+y)-{2xy+(2xy)} =(x+y)-2xy(1+2xy)