Step 1 :
After factoring out $ 5 $ we have:
$$ 20x^{2}-95x-5 = 5 ( 4x^{2}-19x-1 ) $$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 $\color{blue}{ a = 4 }$ by the constant term $\color{blue}{c = -1} $.
$$ a \cdot c = -4 $$Step 4: Find out two numbers that multiply to $ a \cdot c = -4 $ and add to $ b = -19 $.
Step 5: All pairs of numbers with a product of $ -4 $ are:
PRODUCT = -4 | |
-1 4 | 1 -4 |
-2 2 | 2 -2 |
Step 6: Find out which factor pair sums up to $\color{blue}{ b = -19 }$
Step 7: Because none of these pairs will give us a sum of $ \color{blue}{ -19 }$, we conclude the polynomial cannot be factored.