Step 1: 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:
$$ \color{blue}{ b = 95 } ~ \text{ and } ~ \color{red}{ c = 450 }$$Now we must discover two numbers that sum up to $ \color{blue}{ 95 } $ and multiply to $ \color{red}{ 450 } $.
Step 2: Find out pairs of numbers with a product of $\color{red}{ c = 450 }$.
PRODUCT = 450 | |
1 450 | -1 -450 |
2 225 | -2 -225 |
3 150 | -3 -150 |
5 90 | -5 -90 |
6 75 | -6 -75 |
9 50 | -9 -50 |
10 45 | -10 -45 |
15 30 | -15 -30 |
18 25 | -18 -25 |
Step 3: Find out which pair sums up to $\color{blue}{ b = 95 }$
PRODUCT = 450 and SUM = 95 | |
1 450 | -1 -450 |
2 225 | -2 -225 |
3 150 | -3 -150 |
5 90 | -5 -90 |
6 75 | -6 -75 |
9 50 | -9 -50 |
10 45 | -10 -45 |
15 30 | -15 -30 |
18 25 | -18 -25 |
Step 4: Put 5 and 90 into placeholders to get factored form.
$$ \begin{aligned} x^{2}+95x+450 & = (x + \color{orangered}{\square} )(x + \color{orangered}{\square}) \\ x^{2}+95x+450 & = (x + 5)(x + 90) \end{aligned} $$