I have this problem: y=1x and y=.5x+4

I got (2,4) and was wondering if you guys can show me the steps for both elimination and substitution. Also how would I graph this? just put one dot on the graph? (Wondering)

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- Feb 24th 2009, 02:18 PMJubblyElimination and substitution
I have this problem: y=1x and y=.5x+4

I got (2,4) and was wondering if you guys can show me the steps for both elimination and substitution. Also how would I graph this? just put one dot on the graph? (Wondering) - Feb 24th 2009, 02:34 PMReckoner
- Feb 24th 2009, 03:13 PMJubbly
Well, I did 1x=.5x+4

I subtracted .5x from both sides making 1x and .5x

now its .5x=4

divided .5x into 4 and got 2

so x=2?

Can you show me a step by step of how your doing it and how your substituting? - Feb 24th 2009, 03:27 PMReckoner
- Feb 24th 2009, 04:45 PMJubbly
Oh, sorry about that.

If you don't mind can you show me the elimination and substitution equation you used for this. Thanks! - Feb 24th 2009, 05:03 PMReckoner
Certainly. We have

Substitution:

Substituting into the second equation produces

and solving for gives

Back-substituting, we get

Elimination:

Let's first rearrange the equations a little,

Subtract the first equation from the second,

and subtract the second equation from the first: