How do you factor the expression #-10x^2 - 23x - 12#?

1 Answer
Jan 8, 2016

The factorised form for the expression is

#=color(blue)((-5x-4)(2x +3) #

Explanation:

#-10x^2 -23x -12#

We can Split the Middle Term of this expression to factorise it.

In this technique, if we have to factorise an expression like #ax^2 + bx + c#, we need to think of 2 numbers such that:

#N_1*N_2 = a*c = (-10)*(-12) = 120#

AND

#N_1 +N_2 = b = -23#

After trying out a few numbers we get #N_1 = -15# and #N_2 =-8#
#-15*-8 = 120#, and #(-15)+(-8)= -23#

#-10x^2 -23x -12 = -10x^2 -15x-8x -12 #

#=-5x(2x +3) -4(2x+3) #

#=color(blue)((-5x-4)(2x +3) #