8. You just multiply x and y together
For any y-intercept, the x-coordinate is zero. This is something to bear in mind to start with.
Now to find the y-intercept, find g(0) = -2.
Therefore the answer is (0,-2)
Here's what I got for the first question.
Did you want answers for the second one? I couldn't read that part of the image very well, if you did.