# Equations Of Lines Worksheet With Answer Key

2.3 Writing Equations of Lines
In this section you will learn to
• use point-slope form to write an equation of a line
• use slope-intercept form to write an equation of a line
• graph linear equations using the slope and y-intercept
• find the slopes and equations of parallel and perpendicular lines
• recognize and use the standard form of a line
Point-Slope Form
Slope-Intercept Form
The point-slope form of the equation of a nonvertical
The slope-intercept form of the equation of a
nonvertical line with slope m and y-intercept b is
line with slope m that passes through
(
,
)
is
x
y
1
1
=
+
y
mx
b
(
)
y
y
=
m
x
x
1
1
Example 1: Find an equation for the line that passes through the point (-2, 7) and has a slope equal to -5.
Write the equation in point-slope form. Then write the equation in slope-intercept form. (Solve for y.)
Steps:
1. Substitute
,
,
and m values.
x
y
1
1
2. Simplify and solve for y.
3. Check given point and slope (m).
Example 2: Find an equation for the line passing through the points (6, -8) and (4, -3). Write your
equation in point-slope form and then in slope-intercept form.
Steps:
1. Find the slope.
2. Substitute the slope and the
values for one of the points.
3. Simplify and solve for y.
4. Check the point and slope.
Page 1 (Section 2.3)