Linear Equation: an equation whose
graph forms a line.
1143 =− yx
262
+−= xxy
is linear.
is not.
In linear equations, all variables are
taken to the first power.
Linear means of a
line. So a linear equation is the equation
of a line.
Why?
Suppose you were asked to graph the
solution set of the linear equation,
.3=+ yx
You could start by creating a table of
values.
x
y
Choose any number to use as x or y . . .
3=+ yx
x
y
0
3=+ y
. . . and substitute the number for the
variable.
3
0x
3=y
x
y
0
Then calculate to find,
3=+ y
Continue, until you have 3 sets of x and
y values.
3
3x
x
y
0 3
0
3=+x
Continue, until you have 3 sets of x and
y values.
3
x
y
0 3
0
y
6
3−
6
With your table completed for three sets
of values, you are ready to graph the
line.
3
x
y
0 3
0 6
3−
3=+ yx
When x is 0, y is 3, so plot the point,
(0, 3).
3
x
y
0 3
0 6
3−
3=+ yx ( )3,0
And when x is 3, y is 0, so plot the
point, (3, 0).
3
x
y
0 3
0 6
3−
3=+ yx
( )0,3
And finally, when x is -3, y is 6, so
plot the point, (-3, 6).
3
x
y
0 3
0 6
3−
3=+ yx ( )6,3−
If the three points do not line up, you
need to find your mistake.
3
x
y
0 3
0 6
3−
3=+ yx
If they do line up, you just need to
connect the dots.
This is the graph of the linear equation,
.3=+ yx
Create a table of values for each
equation, and graph it on grid paper:
1.
2.
3.
5−=− yx
72 =+ yx
42 −= xy
4. 1
2
1
+= xy

Graphing linear equations

  • 2.
    Linear Equation: anequation whose graph forms a line. 1143 =− yx 262 +−= xxy is linear. is not. In linear equations, all variables are taken to the first power. Linear means of a line. So a linear equation is the equation of a line. Why?
  • 3.
    Suppose you wereasked to graph the solution set of the linear equation, .3=+ yx You could start by creating a table of values. x y
  • 4.
    Choose any numberto use as x or y . . . 3=+ yx x y 0
  • 5.
    3=+ y . .. and substitute the number for the variable. 3 0x 3=y x y 0 Then calculate to find,
  • 6.
    3=+ y Continue, untilyou have 3 sets of x and y values. 3 3x x y 0 3 0
  • 7.
    3=+x Continue, until youhave 3 sets of x and y values. 3 x y 0 3 0 y 6 3− 6
  • 8.
    With your tablecompleted for three sets of values, you are ready to graph the line. 3 x y 0 3 0 6 3− 3=+ yx
  • 9.
    When x is0, y is 3, so plot the point, (0, 3). 3 x y 0 3 0 6 3− 3=+ yx ( )3,0
  • 10.
    And when xis 3, y is 0, so plot the point, (3, 0). 3 x y 0 3 0 6 3− 3=+ yx ( )0,3
  • 11.
    And finally, whenx is -3, y is 6, so plot the point, (-3, 6). 3 x y 0 3 0 6 3− 3=+ yx ( )6,3−
  • 12.
    If the threepoints do not line up, you need to find your mistake. 3 x y 0 3 0 6 3− 3=+ yx If they do line up, you just need to connect the dots.
  • 13.
    This is thegraph of the linear equation, .3=+ yx
  • 14.
    Create a tableof values for each equation, and graph it on grid paper: 1. 2. 3. 5−=− yx 72 =+ yx 42 −= xy 4. 1 2 1 += xy