## kenneyfamily Group Title 4x - y = 1 x + 2y = 7 how could i solve this using an inverse matrix? one year ago one year ago

1. tkhunny Group Title

1) Use the coefficients to form a 2x2 matrix. 2) Augment this matric by I2 3) Perform row operations to find the inverse of the original matrix. Are we ringing bells?

2. kenneyfamily Group Title

No..

3. kenneyfamily Group Title

would you write the matrix as 4 -1 1 2

4. tkhunny Group Title

That is part #1. Very good. Next...

5. kenneyfamily Group Title

what do you mean by augment it by I2?

6. tkhunny Group Title

$\left[\begin{matrix}4 & -1 & 1 & 0\\ 1 & 2 & 0 & 1\end{matrix}\right]$

7. kenneyfamily Group Title

why did you do that? sorry i'm confused

8. tkhunny Group Title

Well, this is one very useful way to find an Inverse Matrix. You've never seen it, before?

9. kenneyfamily Group Title

I may have but I forgot how to do it

10. tkhunny Group Title

How about "Elementary Row Operations"? Any of those floating around in your bag of tricks?

11. kenneyfamily Group Title

I wish I could say yes but no. I'm retaking a pre-calc course because i failed it the first time

12. tkhunny Group Title

Well, you're going to have to get a few things up to speed. Finding an inverse matrix is an important skill. You'll have to start somewhere. Try this: http://www.youtube.com/watch?v=RsTdy2r9DHk

13. kenneyfamily Group Title

ok thanks!!