✔ 最佳答案
Write as 12x^2-17x-5=0
Factor 12x^2-17x-5 - we have to find factors of 12 for the first terms and factors of 5 for the second.
You need to go through all the possibilities in order to make the first term multiply to 12x^2 and the constant term multiply to 5.
(x-5)(12x+1)
(x-1)(12x+5)
(x+5)(12x-1)
(x+1)(12x-5)
(2x-5)(6x+1)
(2x-1)(6x+5)
eventually you start to see when certain groupings won't get us to -17x in the middle. The winner is
(4x+1)(3x-5)
Admittedly, this solution did not just jump out at me either. Sometimes these factoring problems are tedious.