SOLUTION: how do i do this problem? y=2x, x+y=12

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Question 562141: how do i do this problem? y=2x, x+y=12
Answer by TutorDelphia(193) About Me  (Show Source):
You can put this solution on YOUR website!
since we know y=2x I can plug in 2x anywhere I see a y
x+2x=12
combine like terms
3x=12
divide both sides by 3
x=4
plug 4 in for x
y=2*4
y=8