If 2^x = 1/2^y then x+y=??

Question

x, y, z and k are four non zero positive integers satisfying 1/x + y/2 = z/3 + 4/k, minimum integral value of k for integral value of x, y and z will be

Answer 1

zero .........

Answer 2

we have
2^x = 1/2^y
2^x * 2^y =1
2^(x+y) =2^0
on comparing both sides,
we get,
x+y=0