Solving abx−bax=a2−b2 gives x equal to
If x = 1 + a + a2 .......... to ∞ (|a|<1), y = 1 + b + b2 ......... to ∞ (|b| < 1), then Z = 1 + ab + a2 b2 + a3 b3..... to ∞ is