Notes with answers - Summit Schools

Your Notes
Example 2 Draw Quick Graphs
Graph 4x 1 5y 5 20.
1. The equation is already in standard form .
2. Find the x-intercept. 4x 1 5( 0 ) 5 20 Let y 5 0.
SlopES oF parallEl and pErpEndicular linES
Consider two different
nonvertical lines l 1 and l 2
with slopes m 1 and m 2 .
Two lines are parallel if and only
if they have the same slope .
m 1 5 m 2
Two lines are perpendicular if and
only if their slopes are negative
reciprocals of each other.
m 1 5 2 1
}
m 2 or m 1 • m 2 5 –1
x 5 5 Solve for x.
The x-intercept is 5 , so plot the point (5, 0) .
3. Find the y-intercept. 4( 0 ) 1 5y 5 20 Let x 5 0 .
y 5 4 Solve for y.
The y-intercept is 4 , so plot the point (0, 4) .
4. Draw a line through
the intercepts.
Copyright © McDougal Littell/Houghton Mifflin Company Lesson 2.4 • Algebra 2 C&S Notetaking Guide 35
l 1
l 1
1
O
l 2
y
1
O
1
1
O
y
y
1
1
l 2
x
x
x