Just make the equations equal to each other. -0.5x+5=3x-2. Solve for x and find that it is 2, via simple algebra. Since you know x is 2, sub it in in either equation to find y. y should be 4. So the point that fits both equation is (2,4). This shows that the two graphs of these lines will intersect at this exact point.
If you were to graph these two lines, you ould see that the point of intersection is at (2,4) like we solved for.