Question

Create a matrix. use a graphing calculator to solve the system using the rref function.

Answer 1

Answer:

$x=-\dfrac{44}{7}$

$y=\dfrac{58}{7}$

Step-by-step explanation:

Arrange the equations so that all the variables are in columns (x as the first column, y as the second, equals a number as the third):

-11x - 4y = 36

5x + 5y = -10

Define and edit Matrix A.  We need a 3 x 2 matrix.  Input the coefficients and constant:

$\left[\begin{array}{ccc}-11&-4&36\\5&5&-10\end{array}\right]$

Find rref function, enter matrix A:  rref([A])  (press enter)

This gives you:

$\left[\begin{array}{ccc}1&0&-\frac{44}{7}\\0&1&\frac{58}{7}\end{array}\right]$

which means:

$x=-\dfrac{44}{7}$

$y=\dfrac{58}{7}$