How do you factor completely 5x^2 - 23 x + 125x223x+12?

1 Answer
Mar 17, 2016

Use an AC method and factor by grouping to find:

5x^2-23x+12=(5x-3)(x-4)5x223x+12=(5x3)(x4)

Explanation:

We can use an AC method.

Look for a pair of factors of AC = 5*12 = 60AC=512=60 with sum B=23B=23.

The pair 20, 320,3 works.

Use this pair to split the middle term and factor by grouping as follows:

5x^2-23x+125x223x+12

=5x^2-20x-3x+12=5x220x3x+12

=(5x^2-20x)-(3x-12)=(5x220x)(3x12)

=5x(x-4)-3(x-4)=5x(x4)3(x4)

=(5x-3)(x-4)=(5x3)(x4)