Question 110114: graph by first solving for y
x-3y=9
x-9=3y divide both sides by 3
x-3=y or would it be y=1/3x
Am I on the right track and how do you graph a fraction?
Found 2 solutions by Edwin McCravy, stanbon: Answer by Edwin McCravy(20059) (Show Source):
You can put this solution on YOUR website!
graph by first solving for y
x - 3y = 9
get rid of the "x" term on the left by adding -x to both sides:
x - 3y = 9
-x - x
---------------------
-3y = 9 - x
Now divide every term by -3:
= -
Simplify:
= +
This is now solved for y. Next we have to
get some points on the line.
Arbitrarily pick any convenient number to substitute
for x. I think I will first choose 0 to substitute
for x. I chose 0 simply because it is easy. So we
substitute x = 0
= +
= +
= +
=
So one point on the first line is (x, y) = (0,-3)
Let's plot that point. That point is on the
y-axis where y = -3
Now for the second point on the line, I think I will
choose 3 to substitute for x. I chose 3 simply because
the term will be or so it
won't be a fraction. I could have chosen any other
number, but I can avoid fractions by choosing whole
numbers for x that are divisible by 3. So we substitute
x = 3
= +
= +
= +
=
So another point on the first line is (x, y) = (3, -2)
Now let's plot that point. It is directly below 3 on
the x axis and directly to the right of -2 on the
y axis:
We could draw a line through those two points.
However to be on the safe side, we should get
a third point.
Now for the third point on the line, I think I will
choose -6 to substitute for x. I chose -6 simply because
the term will be or so it
won't be a fraction. I could have chosen any other
number, but, as before, I can avoid fractions by choosing
whole numbers for x that are divisible by 3. So we
substitute x = -6
= +
= +
= +
=
So another point on the first line is (x, y) = (-6, -5)
Now let's plot that point. It is directly below -6 on
the x axis and directly to the left of -5 on the
y axis:
Now we draw a straight line through all three
points.
That's the graph of the equation
x - 3y = 9
Edwin
Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! graph by first solving for y
x-3y=9
x-9=3y divide both sides by 3
x-3=y or would it be y=(1/3)x-1
----------------
Plot two points and draw a line thru them:
If x=0 y=-1
If x=3,y=0
----------
Plot the points (0,-1) (3,0)
----------------------
Graph:

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Cheers,
Stan H.
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