How do you factor #x^2+4x - 32#?

1 Answer
Don't Memorise
May 28, 2015

#x^2+4x - 32#

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 = 1*(-32) = -32#
and,
#N_1 +N_2 = b = 4#
After trying out a few numbers we get #N_1 = 8# and #N_2 =-4#
#8*(-4) = -32#, and #8+(-4)= 4#

#x^2+4x - 32 = x^2+8x - 4x - 32#
#x(x+8) -4(x+8)#
#color(green)((x-4)(x+8)#

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