Question

Разложить на множители:
1) c-d-3(d-c)
2) 3c-3d-a(c-d)
3) 3c-3d-a(d-c)

Answer 1

с+d-3c^2+3d^2=c+d+3d^2-3c^2=c+d+3(d^2-c^2)=c+d+3(d-c)(d+c)=(c+d)(1+3d-3c)

Answer 2

1) c-d-3d+3c=4c-4d=4(c-d)
2) 3(c-d)-a(c-d)=(3-a)(c-d)
3) 3(c-d)+a(c-d)=(3+a)(c-d)