      #### Linear system equations and Gauss elimination method

Applying the Gauss elimination's method, the solution of the linear system equations $$\left\{ \begin{array}{l} 2x+y-z=1\\ -x+2y-3z=1\\ 4x+z=2 \end{array} \right.$$ is:
# Matrices
# System of linear equations

Training
13      #### Matrix representation of a system of linear equations

Consider the system of linear equations $$\left\{ \begin{array}{l} x-y+2z=3\\ -3y-z=-5\\ 3x-y+4z=7 \end{array} \right.$$ The second and the fourth columns of the matrix that represents the system are:

# System of linear equations

Training
13     #### Special matrices

Consider the matrices: $A=\begin{bmatrix} 1 & 0 & 0 \\ 0 & 1 & 0 \\ 0 & 0 & 1 \end{bmatrix}$, $B=\begin{bmatrix} 0 & 0 & 0 & 0\\ 0 & 0 & 0 & 0 \end{bmatrix}$, $C=\begin{bmatrix} 1 & 2\\ 3 & 4 \end{bmatrix}$, $D=\begin{bmatrix} 1 \end{bmatrix}$, $E=\begin{bmatrix} 1 \\ 2 \\ 3 \end{bmatrix}$ and $F=\begin{bmatrix} 4 & 3 & 2 & 1 \end{bmatrix}$. Select the true statements:

# Matrices

Training
13      #### Points on a graph

Sketch a the coordinate system. Draw a line through the points A(-5; -4) and B(5; 4). Cross all the correct answers concerning this line.

# Linear functions

Training
8      #### Match the trip with its equation

Chippy the Cheatin’ Chipmunk started at the 4-foot line, he is on a holiday trip with its motorcycle and travels at a constant speed of 12 feet per second. Match the trip with its equation.

# Linear functions

Modeling
8      #### Linear functions at situations practice

Alexandria started at the 4-foot line. She ran up toward the finish line at a constant rate of 7 ft/s. How far in feet will Alexandria be after 8 seconds?

# Linear functions

Modeling
8