разложите на множители 

 

а(x-y)+bx - by

3b-3c+a(b-c)

ab+2(b-d)-ad

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)

licze na naj 

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)