It seems that $ 5x^{2}+2x-8 $ 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 $\color{blue}{ a = 5 }$ by the constant term $\color{blue}{c = -8} $.
$$ a \cdot c = -40 $$Step 3: Find out two numbers that multiply to $ a \cdot c = -40 $ and add to $ b = 2 $.
Step 4: All pairs of numbers with a product of $ -40 $ are:
PRODUCT = -40 | |
-1 40 | 1 -40 |
-2 20 | 2 -20 |
-4 10 | 4 -10 |
-5 8 | 5 -8 |
Step 5: Find out which factor pair sums up to $\color{blue}{ b = 2 }$
Step 6: Because none of these pairs will give us a sum of $ \color{blue}{ 2 }$, we conclude the polynomial cannot be factored.