Answer
Please see step-by-step.
Work Step by Step
$D_{x}$ and $D_{y}$ are determinants used in Cramer's rule for solving linear systems.
If we define $D$ as the determinant of the coefficient matrix,
then we obtain
$D_{x}$ by replacing the 1st column in D with the constants column,
and
$D_{y}$ by replacing the 2nd column in D with the constants column.
