F) 81^15:27^20= [tex] (3^{4}) ^{15} : (3^{3}) ^{20}= 3^{60} : 3^{60}= 3^{60-60}= 3^{0}=1 [/tex]
H) 3^7^2 : 81^12=[tex] 3^{49} : (3^{4})^{12}= 3^{49} : 3^{48}= 3^{49-48}= 3^{1}=3 [/tex]
G) 8^13^2 : 64^84 = [tex] 8^{169} : (2^{6})^{84}= (2^{3})^{169} : 2^{504}= 2^{507}: 2^{504}= 2^{507-504}= 2^{3}=8 [/tex]