Step 1 :
After factoring out $ 2 $ we have:
$$ 2x^{2}+10x-100 = 2 ( x^{2}+5x-50 ) $$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:
$$ \color{blue}{ b = 5 } ~ \text{ and } ~ \color{red}{ c = -50 }$$Now we must discover two numbers that sum up to $ \color{blue}{ 5 } $ and multiply to $ \color{red}{ -50 } $.
Step 3: Find out pairs of numbers with a product of $\color{red}{ c = -50 }$.
PRODUCT = -50 | |
-1 50 | 1 -50 |
-2 25 | 2 -25 |
-5 10 | 5 -10 |
Step 4: Find out which pair sums up to $\color{blue}{ b = 5 }$
PRODUCT = -50 and SUM = 5 | |
-1 50 | 1 -50 |
-2 25 | 2 -25 |
-5 10 | 5 -10 |
Step 5: Put -5 and 10 into placeholders to get factored form.
$$ \begin{aligned} x^{2}+5x-50 & = (x + \color{orangered}{\square} )(x + \color{orangered}{\square}) \\ x^{2}+5x-50 & = (x -5)(x + 10) \end{aligned} $$