`2, 21 . ( 271 + 29 ) + 79 . ( 271 + 29 )`
`= 21 . 300 + 79 . 300`
`= 300 . ( 21 + 79 )`
`= 300 . 100`
`= 30000`
`3, ( 4^5. 10 . 5^6 + 25^5 . 2^8 )/( 2^8 . 5^4 + 5^7 . 2^5 )`
`= ( ( 2^2 )^5 . 2 . 5 . 5^6 + ( 5^2 )^5 . 2^8 )/( 2^8 . 5^4 + 5^7 . 2^5 )`
`= ( 2^11 . 5^7 + 5^10 . 2^8 )/( 2^8 . 5^4 + 5^7 . 2^5 )`
`= ( 2^8 . 5^7 . ( 2^3 + 5^3 ) )/( 2^5 . 5^4 . ( 2^3 + 5^3 ) )`
`= ( 2^8 . 5^7 )/( 2^5 . 5^4 )`
`= 2^3 . 5^3 = ( 2 . 5 )^3`
`= 10^3 = 1000`