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 = 10} $.
$$ a \cdot c = 50 $$Step 3: Find out two numbers that multiply to $ a \cdot c = 50 $ and add to $ b = -51 $.
Step 4: All pairs of numbers with a product of $ 50 $ are:
PRODUCT = 50 | |
1 50 | -1 -50 |
2 25 | -2 -25 |
5 10 | -5 -10 |
Step 5: Find out which factor pair sums up to $\color{blue}{ b = -51 }$
PRODUCT = 50 and SUM = -51 | |
1 50 | -1 -50 |
2 25 | -2 -25 |
5 10 | -5 -10 |
Step 6: Replace middle term $ -51 x $ with $ -x-50x $:
$$ 5x^{2}-51x+10 = 5x^{2}-x-50x+10 $$Step 7: Apply factoring by grouping. Factor $ x $ out of the first two terms and $ -10 $ out of the last two terms.
$$ 5x^{2}-x-50x+10 = x\left(5x-1\right) -10\left(5x-1\right) = \left(x-10\right) \left(5x-1\right) $$