помогите сократить дробь 1)xyz/xz-yz
2)ax-ay/ax+ay
3)3cd+3d/6cd-3d

1) = xyz / z(x-y) = xy / x-y
2) = a(x-y) / a(x+y) = x-y / x+y
3) = 3d(c+1) / 3d(2c-1) = c+1 / 2c-1