Today we will graph linear
equations in slope
intercept form.
y  m x b
y  m x b
 There
are 4 variables in this form of a
linear equation.
 y represents the outcome or output after
you substitute for x.
 x represents the input
 m represents the slope of the line
 b represents the y-intercept (where the
line crosses the y-axis).
y  m x b
 We
can graph the linear equation
quickly if it is in slope intercept
form.
– 1st
plot the value of b on the y-axis
– 2nd
use the slope to find other points
on the line
– 3rd
draw a line through the points
Example 1
1st step
the y axis
plot b on
y  2x  5
Example 1
1st step
the y axis
y  2x  5
plot b on
2nd step
use the
slope to find other points
that are on the line.
Example 1
1st step
the y axis
plot b on
2nd step
use the
slope to find other
points that are on the
line.
3rd step
draw a
line through the points
y  2x  5
Example
2
1st
plot b on the y axis
3
y  x4
4
Example
2
1st step
the y axis
plot b on
2nd step
use the
slope to find other points
that are on the line.
3
y  x4
4
Example
2
1st step
the y axis
plot b on
2nd step
use the
slope to find other
points that are on the
line.
3rd step
draw a
line through the points
3
y  x4
4
You Try It!
1
y  x 8
7
What if the equation is not in slope
intercept form?
Solve the equation for y
 Example:
 4x-3y=18
 -3y=-4x+18
 y = (4/3)x-6


Now you can graph it
because it is in y = mx + b
form.
Try another one!
 Graph
 Solve
x = 7y -21
the equation
for y
 x = 7y -21
 x + 21 = 7y
 7y = x + 21
 y = (1/7)x + 3