matlandia 7 6.3.4 pls

[tex] {64}^{15} = ( {8}^{5} {)}^{6} = {8}^{30} [/tex]
[tex] {64}^{15} = ( {8}^{2} {)}^{15} = {8}^{30} [/tex]
Należy wpisać 8