What's the complete factorization of 10a^2 - 40a + 30?

A) 10 (a - 4) (a - 1)

B) 10 (a - 1) (a - 3)

C) 10 (a + 1) (a + 3)

D) 10 (a - 1) (a + 3)

Ok first you want to reduce down to get the poly into its smallest form. You can do this by dividing by 10 which leaves you with a^2-4a+3. Now you use regular factoring rules. For this equation you need what multiplies to get + 3 and adds to get - 4. Which is a - 1 and a - 3. Now you put it into the blanks to get 10 (a-1) (a-3)