FACTORIZE.... =]

1)
5m^2*n - 10mn^2
= 5mn(m - 2n) (5, m and n are common factors)

2)
abc - 2c + ab - 2
= c(ab-2) + (ab-2) (c is the common factor for first two terms)
= (ab-2)(a+1) ( (ab-2) is the common factor)

3)
ab - 1 - b + a
= ab - b + a - 1
= b(a-1) + (a-1)
= (a-1)(b+1)

4)
ax + 2y - ay - 2z - 2x + az
= ax - ay + az - 2x + 2y - 2z
= a(x-y+z) - 2(x-y+z)
= (x-y+z)(a-2)

1) 5nm^2 - 10mn^2
= 5mn (m-2n)//

2) abc - 2c + ab - 2
= c (ab-2) + (ab-2)
= (c+1) (ab-2)//

3) ab - 1 - b + a
= ab + a - (b + 1)
= a(b+1) - (b+1)
= (a-1) (b+1)//

4) ax + 2y - ay - 2z - 2x + az
= ax - ay + az - (2x - 2y + 2z)
= a(x-y+z) - 2(x-y+z)
= (a-2) (x-y+z)//