How would you get a alone on one side in this equation?
r = ab over a+b
multiply both sides by a+b
ra+rb=ab
subtract ab from both sides.
ra-ab + rb=0
a(r-b)+rb=0
subtract rb from both sides, then divide both sides by r-b
r = ab over a+b
ra+rb=ab
subtract ab from both sides.
ra-ab + rb=0
a(r-b)+rb=0
subtract rb from both sides, then divide both sides by r-b