r = [tex]\frac{3t}{t - 1}[/tex]
multiply both sides of the equation by r - 3
t(r - 3 ) = r ( distribute and collect terms in r together )
tr - 3t = r
tr - r = 3t ( factor out r )
r(t - 1 ) = 3t ( divide both sides by r - 1 )
r = [tex]\frac{3t}{t - 1}[/tex]
