Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Name _______________________________________ Date __________________ Class __________________ Algebra IB 4-5 Practice A Direct Variation Complete the table. 1. y 7x Solve for y (if needed). Is the equation in the form y kx? Is it a direct variation? y 7x yes yes Constant of variation 2. y 4x 10 3. 5x 2y 0 For 4 – 5 , tell whether each relationship is a direct variation. Explain. 4. x 10 15 20 y 2 3 4 6.The value of y varies directly with x, and y 2 when x 4. Find y when x 8. 5. x 4 8 12 y 16 20 24 7.The value of y varies directly with x, and y 12 when x 8. Find y when x 15. 8. The number of hamburgers that can be made varies directly with the weight of ground beef used. Four hamburgers can be produced from every pound of ground beef. Write a direct variation equation for the number of hamburgers y that can be produced from x pounds of ground beef. Then graph the relationship. ________________________________________ Original content Copyright © by Holt McDougal. Additions and changes to the original content are the responsibility of the instructor. Holt McDougal Algebra 1 Name _______________________________________ Date __________________ Class __________________ Practice B Direct Variation Tell whether each equation is a direct variation. If so, identify the constant of variation. 1. y 3x _________________ 2. y 2x 9 _________________ 3. 2x 3y 0 _________________ 4. 3y 9x _________________ For 5 –7 , tell whether each relationship is a direct variation. Explain. 5. x 6 15 21 y 2 5 7 ________________________ 6. x 6 10 25 y 24 40 100 ________________________ 8. The value of y varies directly with x, and y 18 when x 6. Find y when x 8. 7. x 10 15 20 y 3 5 9 ________________________ 9. The value of y varies directly with x, 1 and y when x 5. 2 Find y when x 30. 10. The amount of interest earned in a savings account varies directly with the amount of money in the account. A certain bank offers a 2% savings rate. Write a direct variation equation for the amount of interest y earned on a balance of x. Then graph. ________________________________________ 11. Another bank offers a different savings rate. If an account with $400 earns interest of $6, how much interest is earned by an account with $1800? ________________________________________ Original content Copyright © by Holt McDougal. Additions and changes to the original content are the responsibility of the instructor. Holt McDougal Algebra 1 Name _______________________________________ Date __________________ Class __________________ Practice C Direct Variation Tell whether each equation is a direct variation. If so, identify the constant of variation. 1. y 2x _________________ 2. 8y 3x 1 _________________ 3. 12y 24x _________________ 4. 5x 9y 0 _________________ 5. 6x 3 y _________________ 6. y 4x 8 _________________ For 7–9, tell whether each relationship is a direct variation. Explain. 7. x 3 6 9 y 18 36 54 8. x 8 0 5 y 13 5 0 9. x 1 5 8 y 1.5 7.5 12 ________________________ ________________________ ________________________ ________________________ ________________________ ________________________ ________________________ ________________________ ________________________ 10. The value of y varies directly with x, and y 14 when x 1 . 2 Find y when x 1. ___________________________ 11.The value of y varies directly with x, and y 9 when x 2. Find x when y 22.5. ___________________________ 12.The area a painter can paint varies directly with the amount of time he works. One morning, he painted 204 ft2 between 8 a.m. and 12:15 a.m. Write a direct variation equation to describe the area y covered in x hours. _________________________ 13. The number of people that can be seated in a lecture hall varies directly with the number of rows of seats. If 72 people can be seated in 4 rows, write a direct variation equation to describe the number of people y that can be seated in x rows. Then graph. ________________________ Original content Copyright © by Holt McDougal. Additions and changes to the original content are the responsibility of the instructor. Holt McDougal Algebra 1