Question 245417: Solving Systems by Graphing
could some one show me how to do this
3x-y=3 and 6x+y=5
I have looked in my textbook,looked online i would like to know how to go about sovling these and how to get the plot points so i can graph them.
Thank you
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! Solving Systems by Graphing
could some one show me how to do this
3x-y=3
Solve for y:
y = 3x-3
Plot two or more points:
If x = 0, y = 3*0-3 = -3, giving you point (0,-3)
If x = 2, y = 3*2-3 = 3, giving you point (2,3)
Plot those two points and draw a line thru them
to see the graph.
=============================================
and 6x+y=5
Solve for y:
y = -6x+5
Plot two or more points:
If x = 0, y = -6*0+5 = 5, giving you point (0,5)
If x = 1, y = -6*1+5 = -1, giving you point (1,-1)
Plot those two points and draw a line thru them
to see the graph.
=============================================
To "solve" the system by graphing you have to put
both of those lines on the same coordinate system
and try to determine where the lines intersect.
=============================================
Comment: Most problems of this type have a whole-number
solution pair, like (2,3). Your problem does not so
it is virtually impossible to "solve" the system using
the graphing technique. Try to not let that fact
frustrate your effors.
The real solution to the system is best found using
substitution or elimination. Using substitution you
would get:
3x-3 = -6x+5
9x = 8
x = 8/9
-------------
y = 3x-3
y = 3(8/9)-3 = 8/3 - 9/3 = -1/3
-------------
So the point of intersection of the two lines is
(8/9 , - 1/3)
====================================================
Cheers,
Stan H.
Hope that helps.
Cheers,
Stan H.
-----
|
|
|
