Question

Please Help 

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 = 200 t

Answer 1

Answer:a

Explanation:

Answer 2

`(1)\\the\ domain:\ \ D=\{1;\ 2;\ 3;\ 4\}\ \ \ \ Ans.\ A.\\\\ (2)\ \ \ ? \ (empty)\\\\(3)\\the\ range:\ \ \ Y=\{{1;\ 2;\ 3;\ 4\}\ \ \ \ Ans.\ B.`


`(4)\\ (p)/(d) =const\\\\ (3)/(5) = (12)/(d) \ \ \ \Leftrightarrow\ \ \ 3d=5\cdot12\ \ \ \Leftrightarrow\ \ \ d= (5\cdot3\cdot4)/(3) =20\ \ \ \Rightarrow\ \ \ Ans.\ B.\\\\(5)\\T(z)=z-8\ \ \ \Rightarrow\ \ \ T(-2)=-2-8=-10\ \ \ \Rightarrow\ \ \ Ans.\ A.\\\\(6)\\800\ calories \ \ \rightarrow\ \ 4\ hours\\x\ \ \ \rightarrow\ \ 1\ hour\\\\x= (800)/(4) \ calories\ \ \ \Rightarrow\ \ \ x=200\ calories\\\\C=200\cdot t\ \ \ \Rightarrow\ \ \ Ans.\ C.`