It seems that $ 9n^{2}-30n-25 $ cannot be factored out.
Step 1: 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 2: Multiply the leading coefficient $\color{blue}{ a = 9 }$ by the constant term $\color{blue}{c = -25} $.
$$ a \cdot c = -225 $$Step 3: Find out two numbers that multiply to $ a \cdot c = -225 $ and add to $ b = -30 $.
Step 4: All pairs of numbers with a product of $ -225 $ are:
PRODUCT = -225 | |
-1 225 | 1 -225 |
-3 75 | 3 -75 |
-5 45 | 5 -45 |
-9 25 | 9 -25 |
-15 15 | 15 -15 |
Step 5: Find out which factor pair sums up to $\color{blue}{ b = -30 }$
Step 6: Because none of these pairs will give us a sum of $ \color{blue}{ -30 }$, we conclude the polynomial cannot be factored.