im trying to figure out the answer to my problem because i cant seem to get the answer so if this website can help thank you.

Hi Artavian;

21 = r/3 + 3

I assume this is...

21=(r/3)+3

Let's subtract 3 from both sides...

21-3=(r/3)+3-3

18=r/3

Let's multiply both sides by 3...

(18)(3)=(r/3)(3)

**54=r**

Let's check our work...

21 = (54/3) + 3

21=18+3

21=21