-vp+30<45 subtract 30 from both sides
-vp<15 divide both sides by -v (remember to reverse inequality sign whenever you multiply/divide by a negative value!)
p>-15/v
...
3w-6r=30 divide both sides by 3
w-2r=10 subtract w from both sides
-2r=10-w divide both sides by -2
r=(w-10)/2