Step 1 :
After factoring out $ a $ we have:
$$ 2a^{3}-9a^{2}+12a = a ( 2a^{2}-9a+12 ) $$Step 2 :
Step 2: 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 3: Multiply the leading coefficient $\color{blue}{ a = 2 }$ by the constant term $\color{blue}{c = 12} $.
$$ a \cdot c = 24 $$Step 4: Find out two numbers that multiply to $ a \cdot c = 24 $ and add to $ b = -9 $.
Step 5: All pairs of numbers with a product of $ 24 $ are:
PRODUCT = 24 | |
1 24 | -1 -24 |
2 12 | -2 -12 |
3 8 | -3 -8 |
4 6 | -4 -6 |
Step 6: Find out which factor pair sums up to $\color{blue}{ b = -9 }$
Step 7: Because none of these pairs will give us a sum of $ \color{blue}{ -9 }$, we conclude the polynomial cannot be factored.