Beginning Algebra, 11th Edition

9.Concept Check Match the graph of each line in (a)–(d) with its slope in A–D.

(a) (b) (c) (d)

A. B. C. D.

10.Concept Check Decide whether the line with the given slope rises from left to right,
falls from left to right, is horizontal, or is vertical.

(a) (b) (c) (d)

Concept Check On a pair of axes similar to the one shown,
sketch the graph of a straight line having the indicated slope.

11.Negative

12.Positive

13.Undefined

14.Zero

Concept Check The figure at the right shows a line that has a
positive slope (because it rises from left to right) and a positive
y-value for the y-intercept (because it intersects the y-axis above
the origin).

For each line in Exercises 15–20, decide whether (a)the slope is
positive, negative, or zero and(b)the y-value of the y-intercept is
positive, negative, or zero.

15. 
    
    
    
    16. 
        
        
        
        17. 
            
        
        
        
        
    
    
    
    

m=

3

7

m=- 4 m= 0 m is undefined.

-

3

2

-

2

3

3

2

2

3

SECTION 3.3 The Slope of a Line 207

x

y

0 x

y

0 x

y

0 x

y

0

y

0 x

0 x

y

0 x

y

0 x

y

0 x

y

0

x

y

0 x

y

0 x

18. 
    
    
    
    19. 
        
        
        
        20. y
        
        
        
        
    
    
    
    

21.Concept Check What is the slope (or
grade) of this hill?

22.Concept Check What is the slope (or

pitch) of this roof?

108 m

32 m

6 ft

20 ft