Direct and Inverse Variations

Direct and Inverse Variations

by Suzette Mae Pollenza

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Multiple Choice

Which of the following is a direct variation?

• $$y=kxz$$  

• $$y=\frac{k}{x}$$  

• $$y=kx$$  

• $$y=\frac{kx}{z}$$  

Multiple Choice

Which of the following is an example of Inverse Variation?

• The area of a wall is related to the amount of paint used to cover it.

• The number of tickets sold is related to the amount of money 

• The diameter of a circle is related to its circumference.

• The number of workers is related to the number of days they need to finish a job.

Multiple Choice

If "y varies directly as x," then what is the constant form of Direct Variation?

• $$k=\frac{y}{x}$$  

• $$k=\frac{x}{y}$$  

• $$k=xy$$  

• none of the above

Multiple Choice

If "y varies inversely as x," then what is the constant form of Inverse Variation?

• $$k=\frac{y}{x}$$  

• $$k=\frac{x}{y}$$  

• $$k=xy$$  

• none of the above

Multiple Choice

Identify the type of variation shown in the table of value.

• Inverse

• Direct

• Joint

• Direct and Inverse

Multiple Choice

What is the type of variation and its constant value shown in the given table of values?

• Direct; 200

• Inverse; 200

• Direct; 20,10,200

• Inverse; 100,2,200

Multiple Choice

 If "y varies directly as x," then what is the equation of variation?

• $$y=180x$$  

• $$y=\frac{180}{x}$$  

• $$x=180y$$  

• $$x=\frac{180}{y}$$  

Multiple Choice

If "y varies inversely as x," then what is the variation equation of the given table of values?

• $$x=45y$$  

• $$y=45x$$  

• $$y=\frac{45}{x}$$  

• $$y=\frac{0.2}{x}$$  

Multiple Choice

Which of the following is a direct variation?

• y increases

  x decreases

• y increases

  x increases

• y decreases

  x increases

• all of the above