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January 12th, 2016, 06:24 PM  #1 
Newbie Joined: Jan 2016 From: Auckland Posts: 2 Thanks: 0  Year 11 algebra
x + 2y = 4 2x + 3y = 10 I am really stuck! Last edited by skipjack; January 13th, 2016 at 04:58 AM. 
January 12th, 2016, 06:34 PM  #2 
Global Moderator Joined: Oct 2008 From: London, Ontario, Canada  The Forest City Posts: 7,881 Thanks: 1088 Math Focus: Elementary mathematics and beyond 
Multiply the first equation by 2 and subtract the second equation from the result. That gives you y and x should be easy to find from there.

January 12th, 2016, 06:35 PM  #3 
Newbie Joined: Jan 2016 From: Auckland Posts: 2 Thanks: 0 
When you mean multiply, do you also mutiply the answer of the 1st equation aswell?

January 12th, 2016, 06:59 PM  #4 
Global Moderator Joined: Oct 2008 From: London, Ontario, Canada  The Forest City Posts: 7,881 Thanks: 1088 Math Focus: Elementary mathematics and beyond 
Yes.

January 12th, 2016, 06:59 PM  #5 
Math Team Joined: Jul 2011 From: Texas Posts: 2,774 Thanks: 1428  
January 13th, 2016, 02:36 AM  #6 
Senior Member Joined: Apr 2014 From: Glasgow Posts: 2,132 Thanks: 717 Math Focus: Physics, mathematical modelling, numerical and computational solutions 
This is a simultaneous equation that can be solved either by 1. elimination (the methods Skeeter and Greg are suggesting); or 2. substitution I made a post a few days ago here: I have to solve 3 equations with 3 variables and I'm extremely confused that explains both methods. You can also try the link by Denis on that thread. 

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