Question

Cramers Rule? I am confused

Answer 1

`D` is the determinant of the coefficient matrix:

`D=\begin{vmatrix}3&-1\\-3&5\end{vmatrix}=3*5-(-1)*(-3)=12`

`D_x` is the determinant of the coefficient matrix, but this time you replace the
`x`-coefficients with the values on the right hand side of the equations:

`D_x=\begin{vmatrix}-1&-1\\13&5\end{vmatrix}=(-1)*5-(-1)*13=\boxed{8}`