change the two mixed number into top heavy fractions. 17/5 and 6/5. to add them you get the same denominator (bottom number of the fraction) you can easily do this by multiplying them together - in this instance they both have the same denominator 5 so you can just add the numerators together which will be 23/5. to subtract these fractions you would flip the fraction of the second fraction -> (17/5 x 5/6). once you flip you times numerators by each other and denominators by each other so it’ll be 85/30