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 $\color{blue}{ a = 8 }$ by the constant term $\color{blue}{c = 48} $.
$$ a \cdot c = 384 $$Step 3: Find out two numbers that multiply to $ a \cdot c = 384 $ and add to $ b = -44 $.
Step 4: All pairs of numbers with a product of $ 384 $ are:
| PRODUCT = 384 | |
| 1 384 | -1 -384 |
| 2 192 | -2 -192 |
| 3 128 | -3 -128 |
| 4 96 | -4 -96 |
| 6 64 | -6 -64 |
| 8 48 | -8 -48 |
| 12 32 | -12 -32 |
| 16 24 | -16 -24 |
Step 5: Find out which factor pair sums up to $\color{blue}{ b = -44 }$
| PRODUCT = 384 and SUM = -44 | |
| 1 384 | -1 -384 |
| 2 192 | -2 -192 |
| 3 128 | -3 -128 |
| 4 96 | -4 -96 |
| 6 64 | -6 -64 |
| 8 48 | -8 -48 |
| 12 32 | -12 -32 |
| 16 24 | -16 -24 |
Step 6: Replace middle term $ -44 x $ with $ -12x-32x $:
$$ 8x^{2}-44x+48 = 8x^{2}-12x-32x+48 $$Step 7: Apply factoring by grouping. Factor $ 4x $ out of the first two terms and $ -16 $ out of the last two terms.
$$ 8x^{2}-12x-32x+48 = 4x\left(2x-3\right) -16\left(2x-3\right) = \left(4x-16\right) \left(2x-3\right) $$