5 3/4 + 3 1/6
Make the 3/4 and 1/6 have common denominators. The least common denominator is 12. Multiply 3/4 by 3 on both sides and 1/6 by 2 on both sides.
5 3/4 ⇒ 5 9/12
3 1/6 ⇒ 3 2/12
Now you can add them up.
5 9/12 + 3 2/12 = 8 11/12
The answer is 8 11/12.