• 1
  • 37 Views
  • All levels

Use a matrix to find the solution to the systems of equations

Leave an answer

Our People Answers

1

(Based on todays review)

  • Sicista


    The solutions of the system are:  x=-6 and y=8

    Explanation

    Given system of equations......

    -8x-8y=-16\\ \\ 6x-9y=-108

    First we need to make the augmented matrix using the given equations....

    \left[\begin{array}{cccc}-8&-8&|&-16\\6&-9&|&-108\end{array}\right]

    Now, we need to transform the augmented matrix to the reduced row echelon form using the row operations.

    Row operation 1 :   Multiply the 1st row by -\frac{1}{8}. So, we will get...

    \left[\begin{array}{cccc}1&1&|&2\\6&-9&|&-108\end{array}\right]

    Row operation 2 :   Add -6 times the 1st row to the 2nd row. So, we will get...

    \left[\begin{array}{cccc}1&1&|&2\\0&-15&|&-120\end{array}\right]

    Row operation 3 :   Multiply the 2nd row by -\frac{1}{15}. So, we will get...

    \left[\begin{array}{cccc}1&1&|&2\\0&1&|&8\end{array}\right]

    Row operation 4 :   Add -1 times the 2nd row to the 1st row. So, we will get....

    \left[\begin{array}{cccc}1&0&|&-6\\0&1&|&8\end{array}\right]

    So, this is the reduced row echelon form.

    We can get the equations from the above reduced row echelon form as.....

    1x+0y=-6\\ x=-6 \\ \\ and \\ \\ 0x+1y=8\\ y=8

    So, the solutions of the system are:  x=-6 and y=8