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# Simultaneous equations

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1. I can do the first bit but always get confused with the second
2. (Original post by Jack_Tomlin)
I can do the first bit but always get confused with the second
You now have a -6y and a +6y which will cancel, so add the equations to give 18x+8x = 99+18 -> 26x=117 -> x=4.5.
Now substitute this into any of the equations to give y = -3.
3. What have I messed up?
(Original post by HapaxOromenon3)
You now have a -6y and a +6y which will cancel, so add the equations to give 18x+8x = 99+18 -> 26x=117 -> x=4.5.
Now substitute this into any of the equations to give y = -3.
4. (Original post by Jack_Tomlin)
What have I messed up?

The solution to this is not . If you substitute that in you can see it can't be correct.

Have another go.
5. (Original post by Jack_Tomlin)
What have I messed up?
the very last line

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