# Algerbra Help Needed Fast

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• Nov 7th 2012, 01:14 PM
chris101
Algerbra Help Needed Fast
Anyone got a clue?

x^2+3x-4y+5=2
6=x-2y

thanks
• Nov 7th 2012, 01:25 PM
richard1234
Re: Algerbra Help Needed Fast
Substitute x = 2y+6 into the first equation. Solve for y. Then substitute y into either equation (preferably the second) to find x.
• Nov 7th 2012, 01:26 PM
chris101
Re: Algerbra Help Needed Fast
Can you work the whole thing out? i'm clueless about maths.
• Nov 7th 2012, 01:46 PM
richard1234
Re: Algerbra Help Needed Fast
Generally, I don't post entire solutions as this is a homework help forum. I can't just do the whole problem for you, you won't learn as much. I'll help you get started:

We substitute x = 2y+6 into the first equation:
$(2y+6)^2 + 3(2y+6) - 4y + 5 = 2$.

Expand:
$(4y^2 + 24y + 36) + (6y + 18) - 4y + 5 = 2$

You should be able to simplify the above expression into a quadratic in terms of y. Hopefully you know how to solve quadratics. If you don't, you should review that before continuing on with the problem.