Question 185339
(  )(  )= 12x^2 -9x +16x -12 
Because the sign on the constant (-12) is negative, you know that one term has a plus in it and the other has a minus. You also know that each term has an x in them
(Ax + B)(Cx - D) = 12x^2 -9x +16x -12 
You know that AC = 12, -AD = -9, BC=16 and -BD=-12.
There are only a few pairs of integers that yield a product of 12.
They are (1,12) (2,6) (3,4)
When you look at the inner terms you see a 9 and a 16. 9 is 3*3 and 16 is 4*4, so 3 and 4 are good guesses to try first
Try
(4x + 3)(3x - 4)
You can see that you get 3*3 = 9 and 4*(-4)= -16. The signs don't match the given equation. So flip them
(4x -3)(3x +4)
Now you get -9 and 16. so this looks like a winner