You can put this solution on YOUR website! you are simply adding or subtracting one equation from another trying to eliminate one of the variables. Sometimes you have to manipulate one equation or the other or both to accomplish the elimination.
:
2x+y=5
x-y=7------. these two equation need no help add one to the other and y-y=0 and your left with 2x+x=7+5 and you can solve for x. once you solve for x you can plug its value back into either original equations and solve for y
:
3x+3y=9...eq 1
x-y=10....eq 2----in this case if you multiply all terms in eq 2 by 3 you will get 3x-3y=30........as you can see if you now add the two equations together the y's will again be eliminated because 3y-3y=0 and your left with 3x+3x=9+30 and again you follow the same procedure.
hope that helps
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