Question

Which is a factor of 5xy − 40x − 15y + 120? A. 2 B. y − 8 C. x − 4 D. x + 6

Answer 1

Upon slight rearranging:

5xy-15y-40x+120, now factor 1st and 2nd pair of terms

5y(x-3)-40(x-3) which is equal to:

(5y-40)(x-3)  if we factor the first parenthetical term as well

5(y-8)(x-3)

So (y-8) is a factor