Answer:
(3x-15)(x+1)
Step-by-step explanation:
Given an expression in the form ax²+bx+c, where a,b and c are constants, we can factor it by first finding the two numbers that when multiplied equal to ac and when added equal to b
The expression 3x²-12x-15 can be factored as follows:
The two numbers that can be added to give 3×(-15) and when added result to -12 are -15 and 3.
Thus, 3x²+3x-15x-15
3x(x+1)-15(x+1)
The simplified form becomes: (3x-15)(x+1)