`a` , $4^{8}$ . $8^{4}$
`=` ( $2^{2}$ )$^{8}$ . ( $2^{3}$ )$^{4}$
`=` $2^{16}$ . $2^{12}$
`=` $2^{16+12}$
`=` $2^{28}$
`b` , $5^{12}$ . `7` `-` $5^{11}$ . `10`
`=` $5^{11}$ . $5^{1}$ . `7` `-` $5^{11}$ . `10`
`=` $5^{11}$ . `35``-` $5^{11}$ . `10`
`=` $5^{11}$ ( `35-10` )
`=` $5^{11}$ . `25`
`=` $5^{11}$ . $5^{2}$
`=` $5^{13}$
$c)2^{20}.15+2^{10}.85$
`=` $2^{10}$ . $2^{10}$ . `15` `+` $2^{10}$ . `85`
$=2^{10}(2^{10}.15+85)$
$=1024(15360+85)$
$=1024.15445$
$=15815680$
`=` $2^{10}$ . `5` . `3089`
`d` , $27^{16}$ : $9^{10}$ `=` ( $3^{3}$ ) $^{16}$ : ( $3^{2}$ ) $^{10}$ `=` $3^{48}$ : $3^{20}$ `=` $3^{28}$
`e` , $125^{3}$ : $25^{4}$ `=` ( $5^{3}$ )$^{3}$ : ( $5^{2}$ ) $^{4}$ `=` $5^{9}$ : $5^{8}$ `=` `5`
`f` , $24^{4}$ : $3^{4}$ `-` $32^{12}$ : $16^{12}$
`=` $(24:3)^{4}$ `-` $(32:16)^{12}$
`=` $8^{4}$ `-` $2^{12}$
`=`( $2^{3}$ )$^{4}$ `-` $2^{12}$
`=` $2^{12}$ `-` $2^{12}$
`=` `0`