18. = + 6 y x = 3 y –2x – Solve the system of equations using substitution. 19. 3x + 2y = 7 = + 11 y –3x 20. Solve the system using elimination. 21. 5x + 8y = –29 7x 2y = – –67 22. 2x 2y = – –8 + 2y = x –1 Graph the inequality. 23.
18. y = x + 6 y = –2x – 3 Solve the system of equations using substitution. 19. 3x + 2y = 7 y = –3x + 11 20. Solve the system using elimination. 21. 5x + 8y = –29 7x – 2y = –67 22. 2x – 2y = –8 x + 2y = –1 Graph the inequality. 23.