Express each of the following as an equation.

1. The sum of x and y inversely as p.

2. F is inversely proportional to the sum of q and t.

3. d varies directly as the square root of p.

4. w is directly proportional to the sum of a and b.

5. I is inversely proportional to the square root of the difference between x and y.

6. A varies jointly as x squared and y squared, and inversely as q.