Use matrix method to solve x+4y=8 2x+y=9

In first equation, x has coefficient 1 and y has coefficient 4 and is equal to 8
In first equation, x has coefficient 2 and y has coefficient 1 and is equal to 9

So augmented matrix would looks like this:


Your goal is to transform matrix to look like this:


Steps to reach there:

Subtract first row from second row two times:


Multiple second row by -1/7:


Now subtract second row from first row 4 times:



Which translate to


So then x = 4 and y = 1.

Hope this helps.

Ugucycucucuvuvjvxyxtxu