Originally Posted by
mzeffex
Cool, thanks.
One more I don't get, here's question + answer but I need work.
square both sides, r^2=-20+12r, moving everything to one side gives r^2-12r+20=0. This can be factored into (r-10)(r-2)=0, thus r-10=0, r=10 and r-2=0, r=2.
What level algebra are you in? This stuff is pretty basic
