Question

Will give a medal. Solve the system
{7x+2y=5
{13x+14y=-1
using a matrix.

Answer 1

I know the matrix will look like
[ 7 2| 5]
[13 14| -1]
but don't know how to go forward with it.

Answer 2

Step One: Line up the x, y and constant values. \[7x + 2y = 5 \]\[13x + 14y = -1\]Step Two: Write as equivalent matrices.\[\left[ 7x~~~~~2y \right]\]\[\left[ 13x~~~~14y \right]\]\[= \left[ 5\right]\]\[= \left[ -1 \right]\]

Answer 3

But how do I solve using the matrix? As far as I know I'm supposed to multiply/divide and subtract each row to get to the end result. For example multiply row 7 2 5 by 2.

Answer 4

https://www.khanacademy.org/math/precalculus/precalc-matrices/inverting_matrices/v/matrices-to-solve-a-system-of-equations

Check out that video.

Answer 5

However, I`m slightly confused on how to get 7 2 5 and 13 14 -1 equivalent to each other.

Answer 6

Ok, thanks.