Lesson 7 Extra Practice Equivalent Expressions Simplify each expression. 1. 5x + 3x 8x 2. 2x + x 3x 3. 6x + 8x 14x 4. 9x + 3x 12x 5. 7x + 4x 11x 6. 10x + x 11x 7. 3x + 2 + 4x 7x + 2 8. 15x + 3 + x 16x + 3 9. 2x + 5 + 6x 8x + 5 10. 7x + 2x + 4 9x + 42 11. 18x + 3x + 9 21x + 9 12. 6x + x + 8 7x + 8 Factor each expression. 13. 21x + 15y 3(7x + 5y) 14. 2x + 14y 2(x + 7y) 15. 15x + 10y 5(3x + 2y) 16. 12x + 18y 6(2x + 3y) 17. 10x + 30y 10(x + 3y) 18. 6x + 14y 2(3x + 7y) 19. 8x + 16y 8(x + 2y) 20. 45x + 27y 9(5x + 3y) 21. 54x + 48y