SOLUTION: How do I solve a system of quations using substitution when the euations are y=x+4 y=3x The answer can either be no solution or infinitely many solutions, please explain your wo

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Question 398: How do I solve a system of quations using substitution when the euations are
y=x+4
y=3x
The answer can either be no solution or infinitely many solutions, please explain your work
Answer by arden42(16) About Me  (Show Source):
You can put this solution on YOUR website!
If y=x%2B4 and y=3x then substituting the second equation into the first gives us:
3x=x%2B4
This is now simple to solve for x:
2x=4
x=2
We can now substitute this value into either of the first equations to get the value of y (I'll use the first):
y=2%2B4
y=6
Result:
x=2, y=6. Graphically, this means that the 2 lines intersect at (2,6), as can be seen if we put them onto a graph:
graph%28300%2C200%2C-3%2C6%2C-1%2C8%2Cy=x%2B4%2Cy=3x%29