а(x-y)+bx - by=a(x-y)+b(x-y)=(a+b)(x-y)3b-3c+a(b-c)=3(b-c)+a(b-c)=(3+a)(b-c)ab+2(b-d)-ad=a(b-d)+2(b-d)=(a+2)(b-d)
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