Step 1 :
After factoring out $ -1 $ we have:
$$ -14x^{2}+13x-3 = - ~ ( 14x^{2}-13x+3 ) $$Step 2 :
Step 2: 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 3: Multiply the leading coefficient $\color{blue}{ a = 14 }$ by the constant term $\color{blue}{c = 3} $.
$$ a \cdot c = 42 $$Step 4: Find out two numbers that multiply to $ a \cdot c = 42 $ and add to $ b = -13 $.
Step 5: All pairs of numbers with a product of $ 42 $ are:
PRODUCT = 42 | |
1 42 | -1 -42 |
2 21 | -2 -21 |
3 14 | -3 -14 |
6 7 | -6 -7 |
Step 6: Find out which factor pair sums up to $\color{blue}{ b = -13 }$
PRODUCT = 42 and SUM = -13 | |
1 42 | -1 -42 |
2 21 | -2 -21 |
3 14 | -3 -14 |
6 7 | -6 -7 |
Step 7: Replace middle term $ -13 x $ with $ -6x-7x $:
$$ 14x^{2}-13x+3 = 14x^{2}-6x-7x+3 $$Step 8: Apply factoring by grouping. Factor $ 2x $ out of the first two terms and $ -1 $ out of the last two terms.
$$ 14x^{2}-6x-7x+3 = 2x\left(7x-3\right) -1\left(7x-3\right) = \left(2x-1\right) \left(7x-3\right) $$