SOLUTION: ?Please help me? Solve the system by substitution. x + y = 12 y = 2x

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Question 84500: ?Please help me?
Solve the system by substitution.
x + y = 12
y = 2x
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Solve by substition:
x%2By+=+12
y+=+2x Substitute this value of y into the first equation and solve for x.
x%2B2x+=+12 Combine like-terms.
3x+=+12 Divide both sides by 3.
x+=+4 Now substitute this value of x into the second equation and solve for y.
y+=+2%284%29
y+=+8
The solution is: (4, 8)
You can also see this when you graph these two linear equations.
The solution is the point of intersection of the two lines.
graph%28300%2C200%2C-3%2C6%2C-2%2C16%2C-x%2B12%2C2x%29