7.(-3) (6x')= 14. -4a (a +b-c) 6.(-2) (7x) = 13. -5a (a?- a +3) 5. (4a) (5b) = 20.(-3bc) (a? + b²-2) 12. (5xy) (2x + 6y) 4. (9mn) (8m²n) = 19. (-p) (5p-3pq + 7q) 11. 7x (6x + 4y) 3. (3ab) (6ab) = 18. 9z (1+z+ z') 10. (5ab+ 2b) (2ab) 2. (3a²) (4a?) = 17. m² (am + bm?+ Sm) 9. (2xy) (4xy -3x) = 1. (9a) (5a) = 16. 2k³ (2k²+ 5k - 4) 8. (xy) (x + y) = 15. 5x (x +x*+ 1) Perform the indicated operation:​