first convert the mixed numbers to improper fractions...
rule: a b/c=(ac+b)/c
41/8+79/9
Now to add/subtract fractions you need a common denominator (preferably the least common multiple)
(41/8)(9/9)+(79/9)(8/8)
369/72+632/72
(369+632)/72
1001/72 now back to a mixed number...
(936+65)/72
13 65/72