Answer
$$a= u-2v$$$$b=2u-2v$$ $$c=2u-3.5v$$ $$ d=3u-4v$$
Work Step by Step
Using the graph given in the textbook, follow the dotted grid lines to each point, a-d.
For example, to get to point a, we could either go to the left two times (in the -v direction) and up one time (in the positive u direction), or we could go up once (in the positive u direction) and then down two times (in the negative v direction).
Either sequence yields that $$a=u-2v$$
Use this same strategy, following the grid lines, to find b-d:
$$b=2u-2v$$ $$c=2u-3.5v$$ $$ d=3u-4v$$
