How to solve linear equations using the matrix method 3x-5y=7 -x+y=-1

Answer 1

The augmented matrix is -1 1 -1

3 -5 7

Multiply the first row by -1: 1 -1 1

3 -5 7

Add -3(row 1) to row 2 and replace row 2 with the result:

1 -1 1

0 -2 4

Divide row 2 by -2: 1 -1 1

0 1 -2

Add row 2 to row 1 and replace row 1 by the result:

1 0 -1

0 1 -2

Restore variables: 1x + 0y = -1

0x + 1y = -2

So, x = -1 and y = -2