" Suppose "xy-5x+2y=30," where "x" and "y" are positive integers.Find "

The number of solutions of the equation 2x + y = 40 where both x and y are positive integers and x le y .

If x^yxxy^x=800 , then find x-y (where x and y are positive integers and xgt y ).

If x^yxxy^x=256 ,then find y^2-x^2 where x and y are positive integers and x lt y ).

If x^yxxy^x=72 , then find the sum of x and y where x and y are positive integers (x ne 1 and y ne 1) .

Find the number of solutions for the inequations x + y le 8 and 2x + y le 8 . (where x and y are positive integers)