# Homework Help: Crazy Simultaneous Equation ?

1. Jan 10, 2009

Crazy Simultaneous Equation ?!?

1. The problem statement, all variables and given/known data

Solve for x and y
1)2x - 3y = 1
2)x2 - 2xy - 3y2 = -3

2. Relevant equations

3. The attempt at a solution
I substituted the linear equation into the quadratic and got a quadratic with only y in it:
3.) 15y2 - 2y = 13

I then substituted the linear into eq3 and got a quadratic with only x in it:
4.) 5x2 - 6x = 9

Do I need substitute that linear into these quadratics twice more so I get 2 simultaneous quadratics with only x in them and 2 quadratics with only y in them?

I've been on this question for about half an hour now but this is a sample question from a test so theres no way I could spend that long on a single question on a test. I must be doing it wrong.

Last edited: Jan 10, 2009
2. Jan 10, 2009

### rootX

Re: Crazy Simultaneous Equation ?!?

where is eqn 3?
You say it has only y in it why aren't you solving it then?

3. Jan 10, 2009

Re: Crazy Simultaneous Equation ?!?

Its a quadratic if has y^2 and y. I'll edit the post and put in all the equations I got

4. Jan 10, 2009

### Delphi51

Re: Crazy Simultaneous Equation ?!?

Looks good! The rest is easy - just use one of your techniques for solving a quadratic equation to find the number(s) for y.

5. Jan 10, 2009