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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




Answer :

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

[tex](4)\\ \frac{p}{d} =const\\\\ \frac{3}{5} = \frac{12}{d} \ \ \ \Leftrightarrow\ \ \ 3d=5\cdot12\ \ \ \Leftrightarrow\ \ \ d= \frac{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= \frac{800}{4} \ calories\ \ \ \Rightarrow\ \ \ x=200\ calories\\\\C=200\cdot t\ \ \ \Rightarrow\ \ \ Ans.\ C.[/tex]

Answer:a

Step-by-step explanation: