Hey can you help me fast!!!

Simplify (a/b - b/a) times (a - a^2/a+b) a - a^2/a=b is a mixed number

You are cycling around europe with friends. you book into a hostel and you ask the owner what the ratio of men to women is currently staying there. there are 24 men and 6 women. what is the ratio of men to women in its simplest form?

Kelly is a salesperson at a shoe store, where she must sell a pre-set number of pairs of shoes each month. at the end of each work day the number of pairs of shoes that she has left to sell that month is given by the equation s=300-15x , where s is the number of pair of shoes kelly still needs to sell and x is the number of days she has worked that month. what is the meaning of the number 300 in this equation