8 3/8 = r - 2 1/3 how do i solve this equation by finding out what r is.

First, convert your mixed numbers into improper fractions, so 8+3/8=69/8 and 2+1/3=7/3. Now you have 69/8=r - (7/3). Now, add 7/3 to both sides, so (69/8) + (7/3) = r. Now, just add your fractions, so (69/8) + (7/3) = 207/24+56/24 = (207+56) / 24=263/24. If you need to, this can be converted back into the mixed number 10+23/24.