a)
[tex] {9}^{10} = ( {3}^{2} )^{10} = {3}^{12} [/tex]
[tex] {81}^{7} = ( {3}^{4} )^{7} = 3 ^{28} [/tex]
b)
[tex]4 ^{7} = (2 ^{2} ) ^{7} = 2 ^{14} [/tex]
[tex]8^{11} = ( {2}^{3} ) {}^{11} = 2 ^{33} [/tex]
c)
[tex]125 ^{4} = ({5}^{3} ) {}^{4} = 5 {}^{12} [/tex]
[tex] {25}^{15} =( 5 {}^{2} ) {}^{15} = 5 {}^{30} [/tex]
d)
[tex] {10000}^{6} = (10 {}^{4} ) {}^{6} = 10 {}^{24} [/tex]
[tex] {100}^{9} = ( {10}^{2} ) {}^{9} = 10 {}^{18} [/tex]