SOLUTION: x + y = 12 y = 2x HELP

Question 103558: x + y = 12
y = 2x
HELP
Answer by oberobic(2304) (Show Source): You can put this solution on YOUR website!
One of the way to solve linear equations is to substitute.
In this case, you're given y=2x, so it's ready for substitution.
x+y=12 is the other equation, so substitute the value of y.
x+2x=12
Collecting like terms:
3x = 12
Dividing through by 3:
x = 4
Now go back to first equation: x + y = 12.
We now know x = 4, so it becomes:
4 + y = 12
Subtracting 4 from both sides:
y = 8.
ALWAYS check.
In this case, does y = 2x?
y = 2x
8 = 2*4
8 = 8.
Check!
RELATED QUESTIONS
y=2x x+y=12 (answered by rahman)

y=2x... (answered by tutorcecilia)

y=2x... (answered by stanbon)

y=2x and... (answered by Fombitz)

y=-2x-12... (answered by checkley77)

{x-y=-3... (answered by Alan3354)

x - y = 0 2x + y =... (answered by richwmiller)

2x+y=12 x-y=3 (answered by Sam32399)

2x-y=-3... (answered by Fombitz,Boreal)