#
Section 2-5

#
Slope-Intercept Form of a Linear Equation

A linear equation in the form

**
***
y
*
=
*
mx
*
+
*
b
*
,

where
**
***
x
*
and
**
***
y
*
are the
variables and
**
***
m
*
and
**
***
b
*
are
constants, is said to be in
slope-intercept form
.

Equations in this form are easy to graph, since the
slope
of
line is
**
***
m
*
, and the
*
y
*
-intercept
of
the line (the point where it crosses the
*
y
*
-axis) is
**
***
b
*
.

**
Example:
**

Graph
**
***
y
*
= –2
*
x
*
+ 3
.

Since the equation is given in slope-intercept form, we know immediately
that the line crosses the
*
y
*
-axis at (0, 3) and has slope –2.
We can quickly use the slope to find a second point (1, 1), and graph the line.