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 $\color{blue}{ a = 2 }$ by the constant term $\color{blue}{c = 145} $.
$$ a \cdot c = 290 $$Step 3: Find out two numbers that multiply to $ a \cdot c = 290 $ and add to $ b = 63 $.
Step 4: All pairs of numbers with a product of $ 290 $ are:
PRODUCT = 290 | |
1 290 | -1 -290 |
2 145 | -2 -145 |
5 58 | -5 -58 |
10 29 | -10 -29 |
Step 5: Find out which factor pair sums up to $\color{blue}{ b = 63 }$
PRODUCT = 290 and SUM = 63 | |
1 290 | -1 -290 |
2 145 | -2 -145 |
5 58 | -5 -58 |
10 29 | -10 -29 |
Step 6: Replace middle term $ 63 x $ with $ 58x+5x $:
$$ 2x^{2}+63x+145 = 2x^{2}+58x+5x+145 $$Step 7: Apply factoring by grouping. Factor $ 2x $ out of the first two terms and $ 5 $ out of the last two terms.
$$ 2x^{2}+58x+5x+145 = 2x\left(x+29\right) + 5\left(x+29\right) = \left(2x+5\right) \left(x+29\right) $$