Respostas

2013-12-17T17:58:17-02:00
calcule a expressões:

a) ( 30 + 20 : 5 - 4 ) : ( - 6 + 3 ) =
( 30 + 4 - 4) : (-3)
30 : (-3)
-10

b) ( - 8 ) . ( 3 ) . ( - 1 ) = + 24