How do you factor #2x^2 + 7x-4#?

1 Answer
Aug 28, 2016

Answer:

#2x^2+7x-4=(2x-1)(x+4)#

Explanation:

Use an AC method:

Find a pair of factors of #AC=2*4=8# which differ by #B=7#

The pair #8, 1# works.

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

#2x^2+7x-4#

#=2x^2+8x-x-4#

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

#=2x(x+4)-1(x+4)#

#=(2x-1)(x+4)#