# Homework Help: Determinant systems

1. Dec 26, 2012

### poon

am not a math guru :P,am a newbie even if this should be solved by a newbie as well, Id like u guys to help me out to solve this one :

3x-y+2z=4

Im really needing this, thank you all.

2. Dec 26, 2012

### SteamKing

Staff Emeritus
One equation, three unknowns.

You can solve this equation as long as you pick values for any two of the unknowns.

3. Dec 26, 2012

### poon

can u give me a hand now ? :)
3x+y+2z=4
2x+3y-z=4
2x-y-z=0

4. Dec 26, 2012

### rock.freak667

You could either convert it into a matrix equation and solve it.

Or you can use one equation to modify the other two, and then solve those two simultaneously. For example if you take the last equation and substitute it into the first 2, then solve the now modified first two you will get two of the solutions.

5. Dec 26, 2012

### poon

Thank you guys. But when its up to math in english im not good,actually im not understanding this that much, i need someone to solve it in mathematical view..

6. Dec 26, 2012

### rock.freak667

Do you know how to form a matrix equation from a system of equations?

3x+y+2z=4 (1)
2x+3y-z=4 (2)
2x-y-z=0 (3)

If you take equation 2 and subtract that from equation 3, what equation are you left with?

Similarly, if you take equation 1 and add that to 2*equation 3, what equation are you left with?