SOLUTION: Solve by Substitution Method 2x-4y=3.8 3x-y=17.7 I solved it then I plug in the numbers but it didn't come out right so I need you help!

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Question 741543: Solve by Substitution Method
2x-4y=3.8
3x-y=17.7
I solved it then I plug in the numbers but it didn't come out right so I need you help!
Found 2 solutions by Edwin McCravy, rothauserc:
Answer by Edwin McCravy(20055) About Me  (Show Source):
You can put this solution on YOUR website!
2x - 4y =  3.8
3x -  y = 17.7

Solve the second equation for y:

 3x - y = 17.7
     -y = 17.7 - 3x
    -1y = 17.7 - 3x
    %28-1y%29%2F%28-1%29 = 17.7%2F%28-1%29 - %283x%29%2F%28-1%29
      y = -17.7 + 3x

Substitute (-17.7 + 3x) for y in the first equation:

           2x - 4y = 3.8
2x - 4(-17.7 + 3x) = 3.8
   2x + 70.8 - 12x = 3.8
       -10x + 70.8 = 3.8
              -10x = -67
                 x = %28-67%29%2F%28-10%29
                 x = 6.7  

Substitute (6.7) for x in

      y = -17.7 + 3x
      y = -17.7 + 3(6.7)
      y = -17.7 + 20.1
      y = 2.4

Answer:  (x, y) = (6.7, 2.4)

Edwin

Answer by rothauserc(4718) About Me  (Show Source):
You can put this solution on YOUR website!
we are given
2x-4y=3.8
3x-y=17.7
first note that we can simplify equation one by dividing both sides of the equal sign by 2 and we get
x-2y=1.9 and
x=1.9+2y
substitute for x in the second equation
3*(1.9+2y) - y = 17.7
5.7+6y - y = 17.7
5y = 12 and y = 2.4 and x=1.9+2*2.4=6.7