It seems that $ -q^{2}+18q-25 $ cannot be factored out.
Step 1 :
After factoring out $ -1 $ we have:
$$ -q^{2}+18q-25 = - ~ ( q^{2}-18q+25 ) $$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:
$$ \color{blue}{ b = -18 } ~ \text{ and } ~ \color{red}{ c = 25 }$$Now we must discover two numbers that sum up to $ \color{blue}{ -18 } $ and multiply to $ \color{red}{ 25 } $.
Step 3: Find out pairs of numbers with a product of $\color{red}{ c = 25 }$.
PRODUCT = 25 | |
1 25 | -1 -25 |
5 5 | -5 -5 |
Step 4: Because none of these pairs will give us a sum of $ \color{blue}{ -18 }$, we conclude the polynomial cannot be factored.