How to calculate critical value from test statistic

For which pair of functions is (gof)(a)=|a|-2?

When the solutions to each of the two equations below are graphed in the xy-coordinate plane, the graphs of the solutions intersect at two places. write the y-cordninates of the points of intersection in the boxes below in order from smallest to largest. y=2x y=x^2-3

What are linear equations? could'ya explain too me, ? ! and how do you see what graph is a proportional relationship?