1. (a2)2 2. (b3)2 3. (c4)2 4. (-d5)2 5. (rs)2 6. (m2n2)2 7. (cd2)2 8. (-x3y2)2 9. (2b)2 10. (3x2)2 11. (-4m3)2 12. (-5y4)2 13. (9ab)2 14. (10x2y2)2 15. (-12cd3)2 16. (-15r2s4)2 17. (3/4a)2 18. (5/3c)2 19. (-7/8m)2 20. (-4/5x2)2