Step 1 :
After factoring out $ -2 $ we have:
$$ -16x^{2}-30x+300 = -2 ( 8x^{2}+15x-150 ) $$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 $\color{blue}{ a = 8 }$ by the constant term $\color{blue}{c = -150} $.
$$ a \cdot c = -1200 $$Step 4: Find out two numbers that multiply to $ a \cdot c = -1200 $ and add to $ b = 15 $.
Step 5: All pairs of numbers with a product of $ -1200 $ are:
PRODUCT = -1200 | |
-1 1200 | 1 -1200 |
-2 600 | 2 -600 |
-3 400 | 3 -400 |
-4 300 | 4 -300 |
-5 240 | 5 -240 |
-6 200 | 6 -200 |
-8 150 | 8 -150 |
-10 120 | 10 -120 |
-12 100 | 12 -100 |
-15 80 | 15 -80 |
-16 75 | 16 -75 |
-20 60 | 20 -60 |
-24 50 | 24 -50 |
-25 48 | 25 -48 |
-30 40 | 30 -40 |
Step 6: Find out which factor pair sums up to $\color{blue}{ b = 15 }$
Step 7: Because none of these pairs will give us a sum of $ \color{blue}{ 15 }$, we conclude the polynomial cannot be factored.