Why is the factorization of 2x2+7x+6=(2x+3)(x+2)?

If you factor quadratics with a>1 then you have to find factors of ac that add to give b. So why is the answer 2 and 3 if they don't add to give 7?

1 Answer
Jun 4, 2018

see explanation

Explanation:

given a a quadratic in standard form ;ax2+bx+c

to factor consider the factors of ac which sum to b as
you have stated above

2x2+7x+6 is in standard form

with a=2,b=7 and c=6

the factors of the product 2×6=12

which sum to + 7 are + 4 and + 3

split the middle term using these factors

2x2+4x+3x+6factor by grouping

=2x(x+2)+3(x+2)

take out the common factor (x+2)

=(x+2)(2x+3)

2x2+7x+6=(x+2)(2x+3)