Determine whether varies directly with If so, find the constant of variation. y x. 4. 5. = 1.2x 6. + 4x = 0 y y 7. 3x = 1 8. = 3x 9. + 2 = y y y x For Exercises 10–13, varies directly with y x. 10. If = 3 when = 9, find when = 5. y x x y 11. If = 14 when = 7, find when = 22. y x x y 12. If = 5 when = 8, find when = 2. y x x y 13. If = 4 when = 14, find when = 5. y x y x 14. The distance a spring stretches varies directly with the amount of weight that is hanging on it. A weight of 2.5 pounds stretches a spring 18 inches. What is the stretch of the spring when a weight of 6.4 pounds is hanging on it?
Determine whether y varies directly with x. If so, find the constant of variation. 4. 5. y = 1.2x 6. y + 4x = 0 7. y 3x = 1 8. y = 3x 9. y + 2 = x For Exercises 10–13, y varies directly with x. 10. If y = 3 when x = 9, find x when y = 5. 11. If y = 14 when x = 7, find x when y = 22. 12. If y = 5 when x = 8, find x when y = 2. 13. If y = 4 when x = 14, find y when x = 5. 14. The distance a spring stretches varies directly with the amount of weight that is hanging on it. A weight of 2.5 pounds stretches a spring 18 inches. What is the stretch of the spring when a weight of 6.4 pounds is hanging on it?