Suppose a and b are integers. how many solutions are there to the equation ab = 2a + 3b?

The equation is ab = 2a + 3b
Then,  ab = 2a + 3b
We will solve for "a" we get,
 
1) Add -2a to both the sides of the equation,
 
-2a + ab = 2a + -2a + 3b

On solving we get,

- 2a + ab = 3b

Again we have reached the same equation with which we started. We cannot determine the roots of the equation
 
Thus, There are no solutions to this equation.

221,500 is the answer