Answer:
The answer to your question is 5(x - 3)(x + 3)
Step-by-step explanation:
15x² - 40x - 15
Multiply the first and the last term (15) x (-15) = -225
Find the prime factors of -225
-225 3
- 75 3
- 25 5
- 5 5
-1
Find two numbers that added gives -40 and multiply gives -40 using the prime factors:
These numbers are -45 ( 3 x 5 x 3) and 5
Write -40 as the addition of the numbers just found -40 = -45 + 5
Write the original polynomial using these numbers 15x² - 45x + 5x - 15
Factor by grouping 15x(x - 3) + 5(x - 3)
(x - 3)(15x + 5)
Factor by like terms the second term (x - 3)(5)(x + 3)
