a) 125 . ( -61 ) . ( -2 )³. ( -1 )²n ( n ∈ N* )
= `125` . ( `-61` ) . ( `-8` ) . `n`
= [ `125` . ( `-8` ) ] . ( `-61` ) . `n`
= `-1000` . ( `-61` ) . `n`
= `61000n`
b) 136 . ( -47 ) + 36 . 47
= `-136` . `47` + `36` . `47`
= `47` . ( `36` - `136` )
= `47` . ( `-100` )
= `-4700`
c) ( -48 ) . 72 + 36 . ( -304 )
= ( `-48` ) . ( `36` . `2` ) + `36` . ( `-304` )
= `36` . ( `-48` . `2` ) + `36` . ( `-304` )
= `36` . ( `-96` ) + `36` . ( `-304` )
= `36` . [( `-96` ) + ( `-304` )]
= `36` . ( `-400` )
= `-14400`