Algebra II – 8.1, 8.3 Review Homework Name ________________________ Tell whether x and y show direct variation, inverse variation, or neither. 2. y 1. y = 2x + 3 x 3. x 3 5. The variables x and y vary inversely. Use the given values to write an equation relating x and y. x = 48, y = 1 y x= 12 5b. Using the equation above, find y when x = 0.5 1 xy 2 3 2 6. The variables x and y vary directly. Use the given values to write an equation relating x and y. 4. 1 2 ,y= 1 3 6b. Find y when x = 2 Determine whether x and y show direct variation, inverse variation or neither. 7. 8. 9. The variable z varies jointly with x and y. Use the given values to write an equation relating x, y and z. Then find z when x = 4 and y = 7. 10. x = 6, y = ½ , z = 24 11. x = 3 2 , y = 18, z = 9 12. The number of pages p a student can read varies directly with the amount of time t in minutes spent reading. The student can read 90 pages in 60 minutes. Write the equation that relates p and t. Predict the number of pages the student can read if 90 minutes is spent reading. 13. Product Demand The monthly demand d for one of a company's products varies inversely with the price p of the product. When the price is $8.25, the demand is 5300 units. a) Find the constant of variation k. c) Find the demand if the price is $5.50. 19. Graph: y VA: Domain: x – int.: x y 2x x2 1 HA: _____________ y – int: b) Write an equation that relates d and p. 20. Graph: y 8 x x6 2 VA: HA : Domain: _____________ x – int.: y – int: _______ x y 21. Graph: y x4 x2 3x VA: HA : Domain: _____________ x – int.: y – int: _______ x y 22. Graph: y x2 6x 5 2x 1 VA: HA : Domain: x – int.: _____________ y – int: _______ x y 22. Graph: 3x2 10x 8 y x2 4 VA: HA : Domain: x – int.: x y _____________ y – int: _______