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What is the domain of the function: {(1, 2); (2, 4); (3, 6); (4, 8)}? 
 A.{1, 2, 3, 4, 6, 8}  
B.{1, 2, 3, 4}  
C.{6, 8}  
D.{2, 4, 6, 8}


Which of the following represents a function? 
 A.
  B. 
 C. 
 D.

What is the range of the function: {(2, 1); (4, 2); (6, 3); (8, 4)}?  
A.{1, 2, 3, 4, 6, 8}  
B.{1, 2, 3, 4}  
C.{6, 8}  
D.{2, 4, 6, 8


Suppose p varies directly with d, and p = 3 when d = 5. What is the value of d when p = 12?  A.5/4  B.20  C.14  D.36/5

Given the function T(z) = z – 8, find T(–2). 
 A.–10  
B.–6  
C.10  
D.6

The number of calories burned, C, varies directly with the time spent exercising, t. When Dennis walks for 4 hours, he burns 800 calories. Which of the following equations shows this direct linear variation?  A.C = t  B.C = 800t  C.C = 4t  D.C = 200t