Answer:
First, Outer, Inner, Last: Usually referred to as FOIL for simplicity is a rule for expanding polynomials. It is quite straight forward. You can do as follows for any binomial expression multiplied by a secondary binomial as you have provided.
(3x+1)(2x-1).
Step 1 of FOIL is to multiply the first 2 expressions in your binomials.
(3x)(2x) = 6x^2
Step 2 is to multiply the first by the last
(3x)(-1) = -3x
Step 3 is to do the last by the first
(1)(2x) = 2x
Step 4 is to do the last by the last
(-1)(1) = -1
You are left with the following:
6x^2 -3x + 2x -1
ADD LIKE TERMS!!
6x^2 -x -1
Remember, -x and -1x are the same!
Hope that helps!