SOLUTION: Please Help: My question is on Graphing a System of Linear Equations. The system is: x + y =6 2y - x = 18 According to my book, The equation x + y = 6 passes through (6,

Algebra ->  Coordinate Systems and Linear Equations -> SOLUTION: Please Help: My question is on Graphing a System of Linear Equations. The system is: x + y =6 2y - x = 18 According to my book, The equation x + y = 6 passes through (6,      Log On


   

Question 184303: Please Help:
My question is on Graphing a System of Linear Equations.
The system is:
x + y =6
2y - x = 18
According to my book, The equation x + y = 6 passes through (6,0) and (0,6)
The equation 2y - x = 18 passes through (-18,0) and (0,9)
What I am confused about is how did they come up with -18 for the second equation where they stated that the equation 2y - x = 18 passes through (-18,0) and (0,9)?
I need to know how to get these points with the Graphical Solution Method.
Thank You
Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!




Remember that ordered pairs are of the form (x,y). If the graph of an equation passes through a point, then the coordinates of that point (the x and y in the ordered pair) must make the equation a true statement. So then what is the value of x when y = 0?



The other 3 points were derived in the same way, just by substituting zero for the appropriate variable.



So x = 6 when y = 0 and the point (6,0) is on the line.



So y = 6 when x = 0 and the point (0,6) is on the line.

and for the other equation:



So y = 9 when x = 0 and the point (0,9) is on the line.

John