SOLUTION: please solve the system: x+y=10 y=4x

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Question 56380: please solve the system:
x+y=10
y=4x
Answer by Edwin McCravy(20056) About Me  (Show Source):
You can put this solution on YOUR website!
please solve the system:

  x + y = 10
      y = 4x

The second equation is already solved for y so
substitute 4x in place of y in the first:

  x + y = 10

Putting 4x where y is:

 x + 4x = 10
1x + 4x = 10
     5x = 10
      x = 2

Now substitute 2 for x in the equation y = 4x

      y = 4x
      y = 4(2)
      y = 8

So the solution is (x,y) = (2,8)

Edwin