How do you factor 10x² - 25x -60?

1 Answer
May 19, 2015

You find its roots and then turn them into factors, as follows:

Using Bhaskara:

#(25+-sqrt(625-4(10)(-60)))/20#
#(25+-55)/20#
#x_1=4#, which is the same as the factor #x-4=0#
#x_2=-3/2#, which is the same as the factor #2x+3#

Before factoring, let's just remove the common multiplying constant here:

#10x^2-25x-60=5(2x^2-5x-12)=5(x-4)(2x+3)#