Respuestas

2012-05-27T16:33:04+02:00

-9+{-11-[-5+(-15)-(+23)-9]-12}

-9+{-11-[-5 - 15 -23 - 9 ] -12}

-9+{ -11 + 52 - 12 }

-9 +29

20

2012-05-27T17:07:06+02:00

-9+{-11-[-5+(-15)-(+23)-9]-12}

-9+{-11-[-5 - 15 -23 - 9 ] -12}

-9+{ -11 + 52 - 12 }

-9 +29

20

Espero averte ayudado,, suerte cualquie cosa pone ortos y te explico