Solve the System for X and Y Using Cramer's Rule $$\begin{array} { r } a x + b y = \frac { a } { b } \\x + y = \frac { 1 } { a }\end{array}$$

Multiple Choice

Solve the system for x and y using Cramer's rule. Assume a and b are nonzero constants.
- $$\begin{array} { r } a x + b y = \frac { a } { b } \\x + y = \frac { 1 } { a }\end{array}$$

A) $\left\{ \left( \frac { a + b } { a b } , - \frac { 1 } { b } \right) \right\}$
B) $\left\{ \left( \frac { \mathrm { a } - \mathrm { b } } { \mathrm { ab } } , \frac { 1 } { \mathrm {~b} } \right) \right\}$
C) $\left\{ \left( \frac { a b } { a + b } , - b \right) \right\}$
D) $\left\{ \left( \frac { a b } { a + b } , - \frac { 1 } { b } \right) \right\}$