x(x-y)-y(y-x)
还有一题帮我看看这样做对不对哦
(a+b)^2-2(a+b)
=(a+b)[(a+b)-2]
x(x-y)-y(y-x)
还有一题帮我看看这样做对不对哦
(a+b)^2-2(a+b)
=(a+b)[(a+b)-2]
x(x-y)-y(y-x) =X^2-xy-y^2+xy =x^2-y^2 =(x+y)(x-y)
对的
x(x-y)-y(y-x)
=x(x-y)+y(x-y)
=(x-y)(x+y)
(a+b)^2-2(a+b)
=(a+b)(a+b-2) ................. 大概
第一题应该是x的平方-y的平方
第二题看不懂什么意思
x(x-y)-y(y-x)
=x(x-y)+y(x-y)
=(x-y)(x+y)
(a+b)^2-2(a+b)
=(a+b)(a+b-2)