早教吧 育儿知识 作业答案 考试题库 百科 知识分享

1.(m-n)-(m-n)²2.(a-b)(c+d)-(a-b)(c-d)3.2x(x+y)²+2y(Y+X)²+(x+y)³4.3x(x-2)-2+(2-x)²+x

题目详情
1 .(m-n)-(m-n)²
2.(a-b)(c+d)-(a-b)(c-d)
3.2x (x+y)²+2y(Y+X)²+(x+y)³
4.3x(x-2)-2+(2-x)²+x
▼优质解答
答案和解析
1.
(m-n)-(m-n)²
=(m-n)[1-(m-n)]
=(m-n)(1-m+n)
2.
(a-b)(c+d)-(a-b)(c-d)
=(a-b)[(c+d)-(c-d)]
=2d(a-b)
3.
2x (x+y)²+2y(Y+X)²+(x+y)³
=(x+y)²(2x+2y+x+y)
=3(x+y)²(x+y)
=3(x+y)³
4.
3x(x-2)-2+(2-x)²+x
=3x(x-2)+(x-2)²+(x-2)
=(x-2)(3x+x-2+1)
=(x-2)(4x-1)