That's much better!
Subtract K from both sides:
Multiply both sides by y:
Divide both sides by x- K:
x = k - [(pq)^(1/2)]/y
transpose x to the right and transpose [(pq)^(1/2)]/y to the left
when you transpose, please change your sign to the opposite sign, that is (+ to -) and (- to +).
[(pq)^(1/2)]/y = (k - x)
cross-multiply, obviously y and (k - x) will change places
[(pq)^(1/2)]/(k - x) = y
y = [(pq)^(1/2)]/(k - x)
a latex print will be better to see, i'm too LAZY to learn latex