Solve for $x$ and $y$:

$\frac{x}{a}+\frac{y}{b}=2, ax-by=\left(a^2-b^2\right)$

Solve for $x$ and $y$:
$px+qy=p–q$,

$qx–py=p+q$

Solve for $x$ and $y$:

$\frac{x}{a}-\frac{y}{b}=0, ax+by=\left(a^2+b^2\right)$

Solve for $x$ and $y$:

$ax-by=a^2+b^2, x+y=2a$

Solve for $x$ and $y$:

$\frac{bx}{a}-\frac{ay}{b}+a+b=0, bx-ay+2ab=0$

Solve for $x$ and $y$:

$\frac{bx}{a}+\frac{ay}{b}=a^2+b^2, x+y=2ab$

Solve for $x$and $y$:

$a^{2}x+b^{2}y=c^2, b^{2}x+a^{2}y=d^2$