It seems that $ 9x^{2}-15x+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 = -15 $.
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 $\color{blue}{ b = -15 }$
Step 6: Because none of these pairs will give us a sum of $ \color{blue}{ -15 }$, we conclude the polynomial cannot be factored.