How do you factor 3x^2+7x+2?

1 Answer
May 16, 2016

color(green)((3x + 1 ) (x + 2) is the factorised form of the expression.

Explanation:

3x^2 + 7x + 2

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 = 3*2 = 6

AND

N_1 +N_2 = b = 7

After trying out a few numbers we get N_1 = 6 and N_2 =1

6*1 = 6, and 6 + 1 = 7

3x^2 + 7x + 2 = 3x^2 + color(blue)( 6x + 1 x ) + 2

= 3x(x + 2) + 1 (x + 2 )

(x + 2 ) is a common factor to each of the terms

= color(green)((3x + 1 ) (x + 2)