How do you factor #x^2-8x-48#?

1 Answer
Apr 5, 2016

#x^2-8x-48=(x+4)(x-12)#

Explanation:

To factorize a polynomial of general form #ax^2+bx+c#, one should divide middle term #bx# in two parts, whose sum is #b# and product is #axxc#.

So for #x^2-8x-48#, we should divide #-8x# in two parts which add up to #-8# and whose product is #1xx(-48)=-48#.

A few trial indicate them to be #-12# and #4#. Hence

#x^2-8x-48=x^2-12x+4x-48# or

#x(x-12)+4(x-12)# or

#(x+4)(x-12)#