Direct Variation or Inverse Variation

If s varies directly as t and inversely as v, then which of the following equations describes the relation among the three variables s, t, and v?

• s = k / tv

• s = kv / t

• 1/s = kt/ v

• s = kt / v

Is the given table a direct or inverse variation? What is the constant of variation?

• Direct, 12

• Inverse, 12

• Direct, 1/12

• Inverse, 1/12

Trina's paycheck earnings varies directly as the number of hours she works. If she works 19 hours and earns $187.15, what should she earn if she worked 40 hours?

• $394

• $443.25

• $472.80

• $512.20

Which table represents a direct variation?

• 
• 
• 
• 

Which equation represents an inverse variation?

Which equation represents a direct variation?

Y varies directly to x. If y = 16 when x = 4, which equation represents this situation?

The amount of money earned on a job is directly proportional to the number of hours worked.  If $70.00 is earned in 5 hours, how much money is earned in 22 hours of work?

• $2

• $308

• $1.57

• $265

Given that y varies inversely with x, if x =7 and y = 4, what is y when x = 2?

• 14

• 10

• 2

• -14

The equation 
xy =  25  represents:

• direct variation

• inverse variation

• joint variation

• none of these