19. Answer: 3p^6
Working:
3p^4 x p^2 = 3p^6
(Formula: a^b x a^c = a^b+c)
20.Answer: 42z^8
7z^5 x 6z^3 = 42z^8
(Same formula as Q19)
7. Answer: a^-4 or 1/a^4
a^3 / a^7 = a^-4
(Formula: a^b / a^c = a^b-c)
8. Answer: j^-1 or 1/j
(Same as Q7)
9. Answer: 1
(Same as Q7)
(x^0 = 1)
10. Answer: k^-4
(Same as Q7)
11. Answer: 3x^3/4
(Same as Q7)
(9/12 = 3/4)
12. Answer: 2f^5
13. Answer: (y^8)/2
(Same as Q7)
(4 - (-4)) = (4 + 4)
14. Answer: 1/n^5
(negative power = 1/power)
Sorry got no more time sorry