Answer:
(3x - 5) (x + 3)
Explanation:
Multiply the coefficient of the first term by the constant:
3 x -15 = -45
Find two factors of -45 that equals 4:
-5 + 9 = 4
Rewrite the polynomial splitting 4 using -5 and 9:
3x2 - 5x + 9x - 15
Add up the first 2 terms, pulling out like factors:
x • (3x-5)
Add up the last 2 terms, pulling out common factors:
3 • (3x-5)
Add everything up:
Answer
(x+3) (3x-5)