r=run (x-axis) and s=swim (y-axis)
7r+8s>=336
8s>=-7r+336
x>=-(7/8)r+42
This is a solid line. If you put in 0,0 for r,s respectively, the inequality doesn't work, so that side of the line is not what you want, it is the other. Everything above the line in the first quadrant works.