Answer: (5x - 1)(x + 9)
Explanation:
Please note the method of factoring may differ per class, but this is how I was taught.
First, we will multiply the coefficient of x² by the constant.
5 * -9 = -45
Next, we will find two numbers that add up to 44 (coefficient of x) and multiply to -45 (the number we got above).
-1 * 45 = 45
-1 + 45 = 44
-1 and 45 ✓
Now, we can start to factor. First, we will rewrite 44x.
5x² + 45x - 1x - 9
Then, we will factor by grouping.
5x(x + 9) -1(x + 9) ➜ (5x - 1)(x + 9)
The completely factored form is:
(5x - 1)(x + 9)