We specify a line by giving the slope and one point on the line. We give the first coordinate of some points on the line. Without deriving an equation of the line, find the second coordinate of each of the points.
1. Slope is 2, (1, 3) on line; (2, ); (0, ); (-1, ).
2. Slope is -3, (2, 2) on line; (3, ); (4, ); (1, ).