Find the value of X in the following?

y=a sqr (cx-b/cx+b)
y/a = sqr (cx-b/cx+b)
(y/a) ^ 2 = (cx-b/cx+b)
cxy ^ 2 + by ^ 2 = a ^ 2 cx - a ^ 2 b
a ^ 2 cx - cxy ^ 2 = by ^ 2 + a ^ 2 b
(a ^ 2 c - cy ^ 2) x = by ^ 2 + a ^ 2 b
x = (by ^ 2 + a ^ 2 b)/c(a ^ 2 - y ^ 2)
x = b(y ^ 2 + a ^ 2)/c(a - y)(a + y)