Score Plus

1. If 7x-4y=-1 and 5x+3y=52 then x-y=
a. -4
b. -3
c. 3
d. 4
e. 5

2. If r and s are positive integers, each greater than 1, and if 11(s-1)=13(r-1), what is the least possible value of r+s?
a. 2
b. 11
c. 22
d. 24
e. 26

3. In a certain country, a person is born every 3 seconds and a person dies every 10 seconds. Therefore, the birth and death rates account for a population growth of one person every
a. 3 1/3 sec
b. 4 2/7 sec
c. 7 sec
d. 11 2/3 sec
e. 13 sec

There are also a couple of questions with diagrams. How do I show those to you?

Thanks!