Obtain the solution of the following pair of equations by the cross-multiplication method: $ax + by = 1$ and $bx + ay = \frac{2ab}{a^2 + b^2}$.

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(N/A) The given equations are:
$ax + by - 1 = 0$ --- $(1)$
$bx + ay - \frac{2ab}{a^2 + b^2} = 0$ --- $(2)$
Using the cross-multiplication method:
$\frac{x}{b(-\frac{2ab}{a^2+b^2}) - a(-1)} = \frac{-y}{a(-\frac{2ab}{a^2+b^2}) - b(-1)} = \frac{1}{a^2 - b^2}$
$\frac{x}{\frac{-2ab^2 + a(a^2+b^2)}{a^2+b^2}} = \frac{-y}{\frac{-2a^2b + b(a^2+b^2)}{a^2+b^2}} = \frac{1}{a^2 - b^2}$
$\frac{x}{\frac{a^3 - ab^2}{a^2+b^2}} = \frac{-y}{\frac{b^3 - a^2b}{a^2+b^2}} = \frac{1}{a^2 - b^2}$
$\frac{x}{\frac{a(a^2-b^2)}{a^2+b^2}} = \frac{y}{\frac{b(a^2-b^2)}{a^2+b^2}} = \frac{1}{a^2 - b^2}$
$x = \frac{a(a^2-b^2)}{(a^2+b^2)(a^2-b^2)} = \frac{a}{a^2+b^2}$
$y = \frac{b(a^2-b^2)}{(a^2+b^2)(a^2-b^2)} = \frac{b}{a^2+b^2}$
Thus,the solution is $(x, y) = (\frac{a}{a^2+b^2}, \frac{b}{a^2+b^2})$.

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