1. **State the problem:** Solve the system of equations using determinants (Cramer's Rule):
$$4x - 4y - 8 = 0$$
$$3x + 5 = 2y$$
2. **Rewrite the equations in standard form:**
Equation 1: $$4x - 4y = 8$$
Equation 2: $$3x - 2y = -5$$ (moved all terms to one side)
3. **Write the coefficient matrix and constants vector:**
Coefficient matrix $$A = \begin{bmatrix}4 & -4 \\ 3 & -2\end{bmatrix}$$
Constants vector $$B = \begin{bmatrix}8 \\ -5\end{bmatrix}$$
4. **Calculate the determinant of matrix A:**
$$D = \det(A) = (4)(-2) - (-4)(3) = -8 + 12 = 4$$
Since $$D \neq 0$$, the system has a unique solution.
5. **Calculate determinant $$D_x$$ by replacing the first column of A with B:**
$$D_x = \det\begin{bmatrix}8 & -4 \\ -5 & -2\end{bmatrix} = (8)(-2) - (-4)(-5) = -16 - 20 = -36$$
6. **Calculate determinant $$D_y$$ by replacing the second column of A with B:**
$$D_y = \det\begin{bmatrix}4 & 8 \\ 3 & -5\end{bmatrix} = (4)(-5) - (8)(3) = -20 - 24 = -44$$
7. **Find the values of $$x$$ and $$y$$ using Cramer's Rule:**
$$x = \frac{D_x}{D} = \frac{-36}{4} = -9$$
$$y = \frac{D_y}{D} = \frac{-44}{4} = -11$$
**Final answer:** $$x = -9$$ and $$y = -11$$
Solve System Determinants
Step-by-step solutions with LaTeX - clean, fast, and student-friendly.