Hi, when you multiply both sides by 10, you get \(5(r-45)=2(3-2r)\) because \(10 \div 2 = 5 \text{ and } 10 \div 5 = 2\) .
When you expand the equation you should get \(5r-225=6-4r\).
Moving the variables to one side and constants to another you get \(9r=231\).
Dividing both sides by 9 gets us \(r= 231\div 9\) which equals to \(25 \frac{2}{3}\).
-MPS101