For adding and subtracting fractions always make sure you have common denominators. Multiplication of fractions allows you to multiply fractions across without having common denominators. For mixed fractions, make sure your whole numbers are multiplied by the denominator and then added to the number in the numerator. If you have checked these steps, you should be good to go with your working and solving.
5)7/5+98/15 →LCD=15→7 14/15
6)46/9-17/6 →LCD=18 →2 5/18
7)multiply across → 4/15
8)multiply across (put a 1 under 12 if that helps) 36/4=9
9)23/4×32/3=736/12 → 61 1/3
10)LCD= 8 →1 3/8
11)(put a 1 under 9 if that helps) LCD=3→13 2/3
12)25/6+17/5 →LCD=30 →7 17/30
-E :)