How to factor 15x2+4x-3
Here are 3 ways to factor trinomials, they are pdf files
http://www.mrc.stlmath.com/pdf/allpdf/factri1.pdf
http://www.mrc.stlmath.com/pdf/allpdf/factri2.pdf
http://www.mrc.stlmath.com/pdf/allpdf/factri3.pdf
My personal choice is a variation of the third way, sort of hard to show in this kind of forum
I had the factors (3x-1)(5x + 3) in about 20 seconds.