find the factors of 3, which are 1, 3 or -1, -3, and 24, which can be 1,24; 2,12; 3, 8; 4, 6, negative and positive, and write them this way: factors of 3 to the left, factors of 24 to the right. then multiply diagonally and add up the products. Keep trying different pairs of factors till you make a -17
1 -3
3 -8
1*(-8) + 3(-3) = -17 so (n-3)(3n-8) is the factored form of the expression
