How to solve matrices on a TI-84..? Or something. I'm math stupid 8D

FishBiscuit's picture
Here's this problem I'm trying to solve:
a+b+c=7
d+e+f=3
g+h+i=18


a+d+g=11
b+e+h=15
c+f+i=2
(so you're adding the INITIAL equations across AAAAAND down. yep.)

I put the letters in there for simplicity's sake; they're actually blank ("blank+blank+blank=7") and I'm supposed to solve for the MAGICAL MISSING numbers for a little prize on a dorky pet game I've joined. The numbers can only be between 0 and 9.




I haven't done math in about 2 years so I have NO idea how to approach this. I successfully found my TI-84 calculator and I thought to myself that it looks like a matrix problem, but that's about it.
If somebody can tell me how to solve it, I'll remember it for a while because I used to be able to do this once upon a time.
Zergarikiaka's picture

Hold on I'm grabbing my

Hold on I'm grabbing my TI-84.
I know how to do matricies on it. (Thank you pre-calc. B|)

Edit:

2nd - X-1(Matrix) - Edit - 1:[A]
You'll get a screen saying MATRIX[A] 1 x1
Change the 1 x1 to 3 x3
From there you can start punching in your intervals.
Once you're done, 2nd QUIT.
Then 2nd - X-1(Matrix) - 1:[A]
You'll have your answers.


Since you don't have the numbers (having to fill them in yourself) you'll have to do a little guesswork with that pattern until you have what you need.
FishBiscuit's picture

So what would Matrix [A] look

So what would Matrix [A] look like when I'd enter it? *feels really stupid*

Zergarikiaka's picture

I should be able to find some

I should be able to find some pictures. |D
Basically Matrix [A] is the name of the group you'll make. You can also make a second matrix on Matrix [B], a third in Matrix [C], ect.

This could help: http://www.calcblog.com/matrices-made-easy-ti83-ti84-edition/
WonderfullySarcastic's picture

My math teacher would be so

My math teacher would be so disappointed wtih me ;; I haven't done math in 2 years either and I should know how to do that!
/ashamed
FishBiscuit's picture

*sits in the bandwagon with

*sits in the bandwagon with Wonderful and looks all confused*

Thank you for your help, Zerg! It isn't imperative that I figure it out, so I'll live another day ;D
plus I'm like brain dead right now, so don't feel bad at all lol

Zergarikiaka's picture

No problem. xD

No problem. xD