Step 1: Identify constants $ a $ , $ b $ and $ c $.
$ a $ is a number in front of the $ x^2 $ term $ b $ is a number in front of the $ x $ term and $ c $ is a constant. In this case:
Step 2: Multiply the leading coefficient $\color{blue}{ a = 2 }$ by the constant term $\color{blue}{c = 6} $.
$$ a \cdot c = 12 $$Step 3: Find out two numbers that multiply to $ a \cdot c = 12 $ and add to $ b = 13 $.
Step 4: All pairs of numbers with a product of $ 12 $ are:
PRODUCT = 12 | |
1 12 | -1 -12 |
2 6 | -2 -6 |
3 4 | -3 -4 |
Step 5: Find out which factor pair sums up to $\color{blue}{ b = 13 }$
PRODUCT = 12 and SUM = 13 | |
1 12 | -1 -12 |
2 6 | -2 -6 |
3 4 | -3 -4 |
Step 6: Replace middle term $ 13 x $ with $ 12x+x $:
$$ 2x^{2}+13x+6 = 2x^{2}+12x+x+6 $$Step 7: Apply factoring by grouping. Factor $ 2x $ out of the first two terms and $ 1 $ out of the last two terms.
$$ 2x^{2}+12x+x+6 = 2x\left(x+6\right) + 1\left(x+6\right) = \left(2x+1\right) \left(x+6\right) $$