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| Question 30193:   Solve by using the Gaussian elimination method. For instance:
 5x+2y=3
 3x+4y=13
 I seem to always get stuck on the fractions. Please help in details so I know how to solve more problems like this. Thank You.
 Answer by ikdeep(226)
      (Show Source): 
You can put this solution on YOUR website! 5x+2y=3............(1) 3x+4y=13............(2)
 For elimination we need one variable in both equation to be equal,,,but here we dnt have that,,,so further solution is done in the following ways...
 Multiply (1) by  3 and you get ...
 15x + 6y = 9............(3)
 Multiply (2) by 5 and you get
 15x + 20y = 65............(4)
 Now , by elimination method and subtract (4) from (3)and we get...
 15x + 6y  = 9............(3)
 15x + 20y = 65............(4)
 -   -       -
 -------------------
 - 14y = -56      (15x in both eqautions would be eliminated)
 or     y = -56/-14
 y = 4
 now, substitute the value of y in any of the equation to get the value of x here I am taking (2)...
 3x+4y=13............(2)
 putting the values of y = 4 ,,we get
 3x + 4 * 4 = 13
 3x + 16 = 13
 3x = 13 - 16
 3x = -3
 x = -3/3
 x = -1
 Now if you wanna verify you answer ,,,you can put the values of x and y in any of the equation and if you get LHS=RHS,,,this means that you answer is correct..
 hope this will help you
 Please feel free to revert back for any further queries.
 
 
 
 
 
 
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