Step 1 :
After factoring out $ -2x $ we have:
$$ -2x^{3}+28x^{2}-96x = -2x ( x^{2}-14x+48 ) $$Step 2 :
Step 2: Identify constants $ \color{blue}{ b }$ and $\color{red}{ c }$. ( $ \color{blue}{ b }$ is a number in front of the $ x $ term and $ \color{red}{ c } $ is a constant). In our case:
$$ \color{blue}{ b = -14 } ~ \text{ and } ~ \color{red}{ c = 48 }$$Now we must discover two numbers that sum up to $ \color{blue}{ -14 } $ and multiply to $ \color{red}{ 48 } $.
Step 3: Find out pairs of numbers with a product of $\color{red}{ c = 48 }$.
PRODUCT = 48 | |
1 48 | -1 -48 |
2 24 | -2 -24 |
3 16 | -3 -16 |
4 12 | -4 -12 |
6 8 | -6 -8 |
Step 4: Find out which pair sums up to $\color{blue}{ b = -14 }$
PRODUCT = 48 and SUM = -14 | |
1 48 | -1 -48 |
2 24 | -2 -24 |
3 16 | -3 -16 |
4 12 | -4 -12 |
6 8 | -6 -8 |
Step 5: Put -6 and -8 into placeholders to get factored form.
$$ \begin{aligned} x^{2}-14x+48 & = (x + \color{orangered}{\square} )(x + \color{orangered}{\square}) \\ x^{2}-14x+48 & = (x -6)(x -8) \end{aligned} $$