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把下列各式分解因式,(1)a(x-y)-b(y-x)+c(x-y)(2)(x+y)��-14(x+y)+49请问怎样做

题目详情
把下列各式分解因式,(1)a(x-y)-b(y-x)+c(x-y)
(2)(x+y)��-14(x+y)+49请问怎样做
▼优质解答
答案和解析
(1):a(x-y)-b(y-x)+c(x-y)
=a(x-y)-[-b(x-y)】+c(x-y)
=a(x-y)+b(x-y)+c(x-y)
=(x-y)(a+b+c)
(2):(x+y)��-14(x+y)+49
=(x+y)��-2*7(x+y)+7��
=(x+y-7)