Step 1 :
After factoring out $ 2 $ we have:
$$ 6x^{2}-20x+14 = 2 ( 3x^{2}-10x+7 ) $$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 $\color{blue}{ a = 3 }$ by the constant term $\color{blue}{c = 7} $.
$$ a \cdot c = 21 $$Step 4: Find out two numbers that multiply to $ a \cdot c = 21 $ and add to $ b = -10 $.
Step 5: All pairs of numbers with a product of $ 21 $ are:
| PRODUCT = 21 | |
| 1 21 | -1 -21 |
| 3 7 | -3 -7 |
Step 6: Find out which factor pair sums up to $\color{blue}{ b = -10 }$
| PRODUCT = 21 and SUM = -10 | |
| 1 21 | -1 -21 |
| 3 7 | -3 -7 |
Step 7: Replace middle term $ -10 x $ with $ -3x-7x $:
$$ 3x^{2}-10x+7 = 3x^{2}-3x-7x+7 $$Step 8: Apply factoring by grouping. Factor $ 3x $ out of the first two terms and $ -7 $ out of the last two terms.
$$ 3x^{2}-3x-7x+7 = 3x\left(x-1\right) -7\left(x-1\right) = \left(3x-7\right) \left(x-1\right) $$