15/50 simplified would be 3/10 (divided by 5 on each side)
5/9 x 3/10 would be 15/90 or 1/6
1/4 divided by 3/5 would be 5/12, because when you divide fractions you flip the second fraction Ex: 1/4 divided by 3/5 would be 1/4 x 5/3
The prime factorization of 120 would be 2 x 2 x 2 x 3 x 5 or 2^3 x 3 x 5