Everything you answered so far looks good. Nice work.
For question 10, we need to find two numbers that multiply to 3(-1) = -3 and also add to 2. The 3 and -1 are the first coefficient and last term. The 2 is the middle coefficient.
Through trial and error, the two numbers we're after are 3 and -1
3 times -1 = -3
3 plus -1 = 2
We break up the 2x into 3x - 1x and factor like so...
3x^2 + 2x - 1
3x^2 + 3x - 1x - 1 ... replace 2x with 3x-1x
(3x^2+3x) + (-1x-1) ... pair up terms
3x(x+1) - 1(x+1) .... factor each parenthesis group
(3x-1)(x+1) ... pull out the gcf (x+1)
You can use FOIL, the box method, or distribution to go from (3x-1)(x+1) back to 3x^2+2x-1 again.
The answer to problem 10 is (3x-1)(x+1)