Question

Solve a system using augmented matrices.

x-y=-3
x+3y=5

Answer 1

Can you write the augmented matrix of these equations?

Answer 2

[ 1 -2 l -3] Like this? I don't know how to solve it though
[ 2 3 l 5]

Answer 3

Close. You should have a -1 instead of a -2 though.

Have you been taught how to do row reduction?

Answer 4

No my teacher sucks. And oops, typo.

Answer 5

Ah. That's a bummer. Okay, well the idea of row reduction is the same concept as doing elimination. You only need the coefficients though, since the variables are lined up in the matrix.

So, you want your matrix to look something like:

[ 1 0 | a]
[ 0 1 | b]

Using your first row, what would you need to multiply by to add to your second row to get a 0 in the first column of the second row? (In other words, you want to first get your matrix to look like this:)

[1 -2 | -3]
[0 c | d]

Answer 6

-2