1. MORE ON SLOPES
Algebra 1 – Summer 2013
Mr. Saucedo

2. Objective
 We will learn to compare slopes of
parallel and perpendicular lines.

3. REVIEW: SLOPE IS…
 Rise / run
 Rate of change
 Change in y /
Change in x
 Represented by the
letter “m”
12
12
xx
yy
−
−

4. REVIEW: DESCRIBING SLOPE

5. CORRELATION

6. COMARING POSITIVE SLOPES
Which line has a higher slope?

7. COMPARING NEGATIVE SLOPES

8. Conclusion on comparing slopes

9. Guided practice:
 List in order from
lowest to highest
slope.

10. Parallel lines have equal slope.
m=3 m=-4/5

11. Perpendicular lines have negative
reciprocal slopes.
Slope of red line:
m=3x.
Slope of blue line
m=-1/3

12. Guided pracitce
1. Write an equation that is parallel to
the line: y=10x – 6
2. Write an equation that is
perpendicular to the line: y=10x - 6

13. Guided practice:
 Which equation is perpendicular to
the line y=5x -3?
a. y=5x + 2
b. Y=-5x – 3
c. Y= (1/5) x – 3
d. Y = -(1/5)x

14. Guided Practice
 Which equation is parallel to y=5x –
3
a. Y = -5x
b. Y= 5x
c. Y=(1/5)x – 3
d. Y = -(1/5)x - 3

15. INDEPENDENT PRACTICE
Using the graph:
a. Find an equation of
the line.
b. Find an equation
of a parallel line.
c. Find an equation of
a perpendicular line.
d. Graph lines b and c.

16. INDEPENDENT PRACTICE
1. Which slope is
the most positive?
2. Which slope is
the most negative?