Copyright © by Holt, Rinehart and Winston. 22 Holt MathematicsAll rights reserved.
Name Date Class
Practice BUsing Slopes and Intercepts 12-3
LESSON
Find the x-intercept and y-intercept of each line.Use the intercepts to graph the equation.
1. x � y � �3 2. 2x � 3y � 12
Write each equation in slope-intercept form, and then findthe slope and y-intercept.
3. 3x � y � 0 4. 2x � y � �15 5. x � 5y � 10
Write the equation of the line that passes through each pair ofpoints in slope-intercept form.
6. (3, 4), (4, 6) 7. (�1, �1), (2, �10) 8. (6, 5), (�9, �20)
9. A pizzeria charges $8 for a largecheese pizza, plus $2 for each topping.The total cost for a large pizza is givenby the equation C � 2t � 8, where t isthe number of toppings. Identify theslope and y-intercept, and use them to graph the equation for t between 0 and 5 toppings.
The slt is 8.
b � 0b � 0b � 0
b � �2b � 15b � 0b � 0b � 0b � 0
x-interct is �3;x-interct is �3;x-interct is �3;x-interct is �3;
x
O 4
4
2
2�2
�2
�4
�4
y
xO 8
8
4
4�4
�4
�8
�8
y
20
10
105Number of Toppings
Cost of Large Pizza
Do
llars
MSM07G8_RESBK_Ch12_21-29.pe 2/15/06 10:11 AM Page 22
Copyright © by Holt, Rinehart and Winston. 68 Holt MathematicsAll rights reserved.
Copyright © by Holt, Rinehart and Winston. 19 Holt MathematicsAll rights reserved.
Definition Slope is a ratio.Slope is a measure of the (vertical change compared to slant of a line. horizontal change; �ho
verirztoicnatlal
�)
Lines with Nonzero Slope Horizontal and Vertical Lines Positive slope: The line slants upward Zero slope: from left to right. Horizontal lines have a slope of 0.
Negative slope: The line slants Undefined slope: Vertical lines have andownward from left to right. undefined slope.
Use the graphic organizer to answer the following questions.
1. What do you call the slant of a line?
slope2. Write the ratio that is used to describe slope.
�ho
verirztoicnatlal
chcahnagnege
�
3. How can you tell if a line has positive slope?
The line slants upward from left to right.4. How you can tell if a line has negative slope?
The line slants downward from left to right.5. What kind of line has a slope of 0?
a horizontal line
Reading StrategiesUse a Graphic Organizer12-2
LESSON
Slopeof a Line
Copyright © by Holt, Rinehart and Winston. 20 Holt MathematicsAll rights reserved.
Determine which kind of slope each line has. Then use theletters of the correct answers to solve the riddle.1. 2. 3.
4. 5. 6.
What time do you go to the dentist?
–3 1 1 3 4 4 5 2 3 6
YTRUHHTOOT
Puzzles, Twisters & TeasersA Slippery Slope!12-2
LESSON
x
O
4
4�4
�4
y
x
O
4
4�4
�4
y
x
O
4
4�4
�4
y
x
O
4
4�4
�4
y
O
4
4�4
�4
y
x
O
4
4�4
�4
y
Positive B Negative O Positive R Negative C Positive T Negative NZero D Undefined L Zero Q Undefined D Zero G Undefined N
Positive A Negative T Positive P Negative U Positive J Negative WZero H Undefined V Zero F Undefined Q Zero X Undefined Y
Copyright © by Holt, Rinehart and Winston. 21 Holt MathematicsAll rights reserved.
Practice AUsing Slopes and Intercepts 11-3
LESSON
1. Name the ordered pair if the x-intercept is �2.
2. Name the ordered pair if the y-intercept is 8.
3. In the ordered pair (9, 0), what is the x-intercept?
4. In the ordered pair (0, 0), what is the relationship of the x-intercept and y-intercept?
Find the x-intercept and y-intercept of each line. Use theintercepts to graph the equation.
5. x � y � 5 6. 2x � y � 6
Write each equation in slope-intercept form, and then find theslope and y-intercept.
7. 2x � y � �5 8. x � y � 10 9. x � 2y � 4
Write the equation of the line that passes through each pair ofpoints in slope-intercept form.
10. (1, 2), (�1, 0) 11. (1, �3), (�1, 1) 12. (1, 1), (�3, �3)
y � xy � �2x � 1y � x � 1
m � �12
�; b � �2m � 1; b � �10m � �2; b � �5
y � �12
�x � 2;y � x � 10;y � �2x � 5;
y-intercept is �6y-intercept is 5
x-intercept is 3;x-intercept is 5;
x-intercept � y-intercept
9
(0, 8)
(�2, 0)
xO 8
8
4
4�4
�4
�8
�8
y
xO 8
8
4
4�4
�4
�8
�8
y
Copyright © by Holt, Rinehart and Winston. 22 Holt MathematicsAll rights reserved.
Practice BUsing Slopes and Intercepts 12-3
LESSON
Find the x-intercept and y-intercept of each line.Use the intercepts to graph the equation.
1. x � y � �3 2. 2x � 3y � 12
Write each equation in slope-intercept form, and then findthe slope and y-intercept.
3. 3x � y � 0 4. 2x � y � �15 5. x � 5y � 10
Write the equation of the line that passes through each pair ofpoints in slope-intercept form.
6. (3, 4), (4, 6) 7. (�1, �1), (2, �10) 8. (6, 5), (�9, �20)
9. A pizzeria charges $8 for a largecheese pizza, plus $2 for each topping.The total cost for a large pizza is givenby the equation C � 2t � 8, where t isthe number of toppings. Identify theslope and y-intercept, and use them to graph the equation for t between 0 and 5 toppings.
The slope is 2, and the y-intercept is 8.
y � �53
�x � 5y � �3x � 4y � 2x � 2
b � �2b � 15b � 0
y � �15
�x � 2; m � �15
�;y � 2x � 15; m � 2;y � �3x; m � �3;
y-intercept is 4y-intercept is 3x-intercept is 6; x-intercept is �3;
xO 4
4
2
2�2
�2
�4
�4
y
xO 8
8
4
4�4
�4
�8
�8
y
20
10
105Number of Toppings
Cost of Large Pizza
Do
llars
MSM07G8_RESBK_Ch12_64-xx.pe 2/15/06 10:30 AM Page 68
