Remember that to add/subtract fractions you need a common denominator...
3/(r-2)+1/r=0 so we need r(r-2) as the common denominator...
3r/(r(r-2))+(r-2)/(r(r-2))=0 we can cancel out the r(r-2) by multiplying the whole equation by it leaving us with:
3r+r-2=0 combine like terms
4r-2=0 add 2 to both sides
4r=2 divide both sides by 4
r=1/2
