How do you factor by grouping #12x^2-7x-5#?
The trick is to find how to split the middle
The split comes from a pair of factors of
When a + b + c = 0, you are advised to use the Shortcut.
One factor is (x - 1) and the other is (-c/a = 5/12).
y = (x - 1)( 12x + 5)