SOLUTION: How would I graph these equations: (a) y = x + 3 (b) y = -1/3x (c) y = 1/3x (d) y = 3x?? If possible could you please show me how to graph all 4, because the more you show me, the

Algebra ->  Graphs -> SOLUTION: How would I graph these equations: (a) y = x + 3 (b) y = -1/3x (c) y = 1/3x (d) y = 3x?? If possible could you please show me how to graph all 4, because the more you show me, the       Log On


   

Question 120986: How would I graph these equations: (a) y = x + 3 (b) y = -1/3x (c) y = 1/3x (d) y = 3x?? If possible could you please show me how to graph all 4, because the more you show me, the easier it is for me to catch on. Graphing is very difficult for me.
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
How would I graph these equations: (a) y = x + 3
:
Choose some values for x, let's use 3 values: x = -3; x = 0; x = +3
(You actually only need two for linear equations)
:
We are going to substitute each value in the above equation to find y:
For x = -3:
y = (-3) + 3
y = 0
:
For x = 0:
y = (0) + 3
y = 3
:
For x = +3
y = (3) + 3
y = 6
:
Make an x/y table from the above values
x | y
-------
-3 | 0
0 |+3
+3 | 6
:
Plot each of these x/y values and join them with a straight line
You graph should look like this
:
+graph%28+300%2C+200%2C+-6%2C+5%2C+-8%2C+8%2C+x%2B3%29+
:
:
(b) y = -1/3x; use the the same x values for this one, find y
For x -3
y = -1/3(-3)
y = +1
:
For x = 0
y = -1/3(0)
y = 0
:
For x =+3
y = -1/3(3)
y = -1
:
Make an x/y table from the above values
x | y
-------
-3 |+1
0 | 0
+3 |-1
Plot these x/y values, you graph should look like this:
+graph%28+300%2C+200%2C+-6%2C+5%2C+-4%2C+4%2C+%28-1%2F3%29x%29+

(c) y = 1/3x y; use the the same x values for this one, find y
For x -3
y = 1/3(-3)
y = -1
:
For x = 0
y = 1/3(0)
y = 0
:
For x =+3
y = 1/3(3)
y = +1
:
Make an x/y table from the above values
x | y
-------
-3 |-1
0 | 0
+3 |+1
Plot these x/y values, you graph should look like this:
+graph%28+300%2C+200%2C+-6%2C+5%2C+-4%2C+4%2C+%281%2F3%29x%29+
:
:
(d) y = 3x; use the the same x values for this one, find y
For x -3
y = 3(-3)
y = -9
:
For x = 0
y = -3(0)
y = 0
:
For x =+3
y = 3(3)
y = +9
:
Make an x/y table from the above values
x | y
-------
-3 |-9
0 | 0
+3 |+9
Plot these x/y values, you graph should look like this:
+graph%28+300%2C+200%2C+-6%2C+5%2C+-10%2C+10%2C+3x%29+
:
Note that I changed the scale of the graphs slightly to improve the illustration.
You can do all these on standard -10,+10 scale graph paper
:
Did this enlighten you to the graphing world? Any questions?