Question

Solve the following system of equations.
4x-2y-z=-5
x-3y+2z=3
3x+y-2z=-5

Answer 1

Learn cramer's rule and you'll have no problem with solving systems such as these

Answer 2

You can use Cramer's rule, or generate an augmented coefficient matrix and either perform row reduction to get the answer (or the inverse), or use the long, drawn-out analytic way (with the matrix of cofactors and transposes) to get an inverse matrix. Once you have an inverse, you can just multiply it by the right-hand vector, but using Cramer's rule is much simpler.

Answer 3

What is cramer's rule ?

Answer 4

http://en.wikipedia.org/wiki/Cramer%27s_rule

It's important to understand how it works, and once you know, you'll never forget it (it's pretty intuitive). It provides very fast results.

Answer 5

Go down to "Explicit formulas for small systems".

Answer 6

For three variable systems, I wouldn't suggest anything else.

Answer 7

This one's pretty easy though. Wouldn't take more than 3 or 4 minutes to bring it down with row reduction.

Answer 8

Right, I was assuming the person didn't know how to solve using matrices

Answer 9

Both are techniques you'd learn in a precalculus or introductory linear algebra course, but you're right - Cramer's rule is pretty much always much simpler and quicker. Less prone to silly arithmetical mistakes, too.

Answer 10

I could have learned cramers rule when I took algebra for the first time. Not that difficult. Don't know why they avoided teaching it to me when I was a freshie in hs

Answer 11

There's a lot of baggage associated with linear systems that would logically precede and follow from learning Cramer's rule... it's not difficult for a freshman in high school to learn, but it's just not incredibly relevant (you'd have to invoke matrices, determinants, etc).

Answer 12

At the very least learning what a 2 x 2 matrix and its determinant would have been a very innocently harmless introduction to what was to come in the future. Better to go into something with one eye rather than with blind eyes.

Answer 13

0.) Given:

4x-2y-z=-5
x-3y+2z=3
3x+y-2z=-5

1.) Add the 2nd and 3rd Equations together to eliminate z:
4x - 2y = -2

2.) Multiply the first equation by 2
8x - 4y -2z = -10

3.) Add the above result to the second equation to get:
9x - 7y = -7

4.) Use the equations from steps 1.) and 3.) to solve the following system:

4x - 2y = -2
9x - 7y = -7

Answer 14

I got you started.

Answer 15

I still don't know . Im just gunna quit and move on .

Answer 16

I'm sorry to hear that you're going to quit.

Answer 17

You don't know how to solve system of two equations?

Answer 18

is it..... (0, 1, 3) ???

Answer 19

Yes. I'm not going to even ask how you got that

Answer 20

Hahahahahahaha , okkaaay . :p Thank you though !