Chapter 3 - Equations and Problem Solving - 3.1 - Solving First-Degree Equations - Problem Set 3.1 - Page 100: 74

$54=r$

We start with the given equation: $d=rt$ We plug in the values for $d$ and $t$: $486=9r$ We are trying to get $r$ by itself. In order to do so, we must divide by $9$ on each side of the equation and then simplify: $$\frac{486}{9}=\frac{9r}{9}$$$$54=r$$