Ok so lets evaluate this equation. First,we have to combine like terms which in this case us r only. So lets do it r+8r is simply 9r+11=29 so now since we want to isolate or in other terms get r the variable by itself we would have to subtract 11 form both sides. 29 -11 is simply 18 now we have 9r=18 divide 9 on both sides and r is equal to 2