History of Hindu Mathematics: A Source Book v2.c17.s21.35

v2.c17.s21.35

What is implied is this: Multiplying both sided of the given equation by *a*, we get $a²y² = abx ± ac,$ Put u = ay, v = ax. Then the equation reduces to $u² = bv ± ac,$ which can be solved in the way described before.