Plot y vs x with multiple terms/variables?

GROUPS:
 I am trying to plot a ( $y$ vs $x$ style) graph with Wolfram Alpha, but the syntax needed is a little more involved.I started with: b=(v*((0.2)/(r/2+0.2))),p=((v-b)^2/r),v=6.6,r=5which solves a single number for p. That's what I wanted.But now I want to graph p as the dependent variable and r as the independent. Here are some examples that don't work: b=(v*((0.2)/(r/2+0.2))),p=((v-b)^2/r),v=6.6, graph p vs r b=(v*((0.2)/(r/2+0.2))),p=((v-b)^2/r),v=6.6 plot p plot b=(v*((0.2)/(r/2+0.2))),p=((v-b)^2/r),v=6.6 from r=1 to 20 None of those result in a graph.As you can see, I'm not versed enough in the Wolfram Alpha syntax to pull this off unless I use the more simple plot x^2+1 style.How can I graph p vs r? Ideally, I want to leave the different "pieces"/"terms" (what do I call those?) as separate parts. (I don't want to combine b=(v*((0.2)/(r/2+0.2))) and p=((v-b)^2/r), and I want to have separately defined constants like v)