Question

Factor completely 3x^2+ 2x -1.

O (3x + 1)(x - 1)
O (3x + 1)(x + 1)
O (3x - 1)(x + 1)
O (3x - 1)(x - 1)

Answer 1

option C

Explanation:

`3x^2+2x-1\\\\=(3x+a)(x+b)\\\\(3b+a)=2\\\\ab=-1`

and here we think of b=1 and a=-1

so we have

`(3x-1)(x+1)`