Question

Responda (+2)+(+1)
(+3)+(+9)

Answer 1

Resposta:

> regra de sinais:

( + ) com ( + ) = ( + )

( - ) com ( - ) = ( + )

( + ) com ( - ) = ( - )

( - ) com ( + ) = ( - )

______________

( + 2 ) + ( + 1 ) ( + 3 ) + ( + 9 )

= ( + 2 ) + 3 + ( + 9 )

= 5 + ( + 9 )

= +14

ou

( + 2 ) + ( + 1 )

= 2 + 1

= + 3

( + 3 ) + ( + 9 )

= 3 + 9

= + 12