In Problems 13-24, find the intercepts and graph each equation by plotting points. Be sure to label the intercepts. 13. y = x + 2 14. y = x - 6 15. y = 2x + 8 16. y = 3x - 9
17. y = x² - 1 18. y = x² - 9 19. y = -x² + 4
20. y = -x² + 1 21. 2x + 3y = 6 22. 5x + 2y = 10 23.9x² + 4y = 36 24. 4x² + y = 4