Graph the system and determine the number of solutions that it has. If it has one solution, name it.

$$\begin{aligned} & x+2 y=4 \\ & y=-\frac{1}{2} x+2 \end{aligned}$$

Use substitution to solve the system of equations.

$$\begin{aligned} & x+5 y=4 \\ & 3 x+15 y=-1 \end{aligned}$$

Use an augmented matrix to solve the system of equations.

$$2 x+5 y=1$$

$$-x-y=-2$$

Use substitution to solve the system of equations.

$$\begin{aligned} & x+2 y=13 \\ & 3 x-5 y=6 \end{aligned}$$

Perform the indicated matrix operations. If the matrix does not exist, write impossible.

$$5\left[\begin{array}{rr}1 & -4 \\ 0 & 3\end{array}\right]$$

Use substitution to solve the system of equations.

$$x+14 y=84$$

$$2 x-7 y=-7$$

Use elimination to solve the system of equations.

$$3 x-y=26$$

$$-2 x-y=-24$$

Graph the system and determine the number of solutions that it has. If it has one solution, name it.

$$\begin{aligned} & x-y=3 \\ & x-2 y=3 \end{aligned}$$

Use an augmented matrix to solve the system of equations.

$$x+4 y=19$$

$$-3 x-2 y=-7$$

Use elimination to solve the system of equations.

$$7 x+2 y=2$$

$$7 x-2 y=-30$$

Use elimination to solve the system of equations.

$$3 x-6 y=-3$$

$$2 x+4 y=30$$

Use elimination to solve the system of equations.

$$3 x+2 y=11$$

$$2 x+6 y=-2$$

Perform the indicated matrix operations. If the matrix does not exist, write impossible.

$$5\left[\begin{array}{rrrr}0 & 2 & -1 & 7 \\ 4 & 1 & 0 & 2 \\ -3 & 1 & 9 & -4 \\ 0 & -2 & 6 & 1\end{array}\right]$$

Use elimination to solve the system of equations.

$$6 x-3 y=21$$

$$2 x+2 y=22$$