Answer
$x= 8$
$y= 4$
$z = 2$
$w = 1$
Work Step by Step
Given:
$x + y + z + w = 15$
$x - y + z - w = 5$
$x + 2y + 3z + 4w = 26$
$x - 2y + 3z - 4w = 2$
The question asks for a graphing calculator to solve the system of equations. The calculations were done on desmos.com/matrix
Convert the linear system into a matrix equation.
Below shows A and B as a matrix equation from the linear system:
$A=\left[\begin{array}{ll}
1 & 1 & 1 & 1\\
1 & -1 & 1 & -1\\
1 & 2 & 3 & 4\\
1 & -2 & 3 & -4
\end{array}\right]$
$B=\left[\begin{array}{l}
15\\
5\\
26\\
2
\end{array}\right]$
Then the calculator finds the inverse of A (see $A^{-1}$ below)
To determine matrix X, the solution, multiply the inverse of A by B (see $A^{-1}B$ below)
The answers are below:
$x= 8$
$y= 4$
$z = 2$
$w = 1$