91Ó°ÊÓ

\(\begin{aligned} \frac{5}{x}-\frac{1}{y}-\frac{2}{z} &=-6 \\ -\frac{1}{x}+\frac{3}{y}-\frac{3}{z} &=-12 \\ \frac{2}{x}-\frac{1}{y}-\frac{1}{z} &=6 \end{aligned}\)

Evaluate each determinant. $$\operatorname{det}\left[\begin{array}{rrrr}4 & 5 & -1 & -1 \\\2 & -3 & 1 & 0 \\\\-5 & 1 & 3 & 9 \\\0 & -2 & 1 & 5\end{array}\right]$$

Solve each system by using the matrix inverse method. $$\begin{aligned} &2 x+3 y=-10\\\ &3 x+4 y=-12 \end{aligned}$$

Evaluate each determinant. $$\operatorname{det}\left[\begin{array}{rrrr}4 & 0 & 0 & 2 \\\\-1 & 0 & 3 & 0 \\\2 & 4 & 0 & 1 \\\0 & 0 & 1 & 2\end{array}\right]$$

Use row operations on an augmented matrix to solve each system of equations. Round to nearest thousandth when appropriate. $$\begin{aligned} &2 x-3 y=2\\\ &4 x-6 y=1 \end{aligned}$$

Solve each system by elimination. $$\begin{array}{r}9 x-5 y=1 \\\\-18 x+10 y=1\end{array}$$

\(\begin{aligned} &x-4 y+2 z=-2\\\ &x+2 y-2 z=-3\\\ &x-y \quad=4 \end{aligned}\)

Checking Analytic Skills Graph the solution set of each system of inequalities by hand. Do not use a calculator. $$\begin{array}{r}2 x+y>2 \\\x-3 y<6\end{array}$$

Solve each system by using the matrix inverse method. $$\begin{aligned} &2 x-3 y=10\\\ &2 x+2 y=5 \end{aligned}$$

Use row operations on an augmented matrix to solve each system of equations. Round to nearest thousandth when appropriate. $$\begin{array}{r} x+2 y=1 \\ 2 x+4 y=3 \end{array}$$