Consider the equation x^2+y^5=z^3 where x, y, and z, are positive integers.
(A) Can you give at least three solutions to it?
(B) Determine whether or not there is an infinite number of solutions.
If x=2^5P and y=2^2P, the left hand side of the equation is 2^(10P+1), so 10P+1 must be a multiple of 3. Letting P=3K+2, 10P+1 becomes 30K+21, so
x=2^(15K+10), y=2^(6K+4), z=2^(10K+7) is a solution for all K.