Factor 3y^2 + 5y - 12

(3y - 4) (y + 3)

Step-by-step explanation:

Expression: 3y² + 5y - 12

My preferred method of factoring is to find two numbers that add up to bx and has the product of acx² (when ax² + bx + c), substituting those numbers in for bx, and factoring that way. So here;

Numbers: - 4y, 9y

Substitute: 3y² - 4y + 9y - 12

Factor: (3y - 4) (y + 3)