Answer:
In the first one you are missing (x - 3) so it will be 4(x - 3) and if you factor it out it will be 4x - 12
In the second one you are missing a (x -5)which means 9x(x -5) or when you factor it out it will be 9x^2 - 45x
Explanation:
3x^2 -23x + 40 = (3x - 8) (x - 5)
3x^2 -17x + 24 = (3x -8) ( x - 3)