1+{2+[3×(4+5)-6+7×8]-9}

Răspuns :

1+[ 2+(3x 9 - 6+56)-9] =

1+[2+(27-6+56)-9]=

1+[2+(21+56)-9]=

1+(2+77-9)=

1+(79-9)=1+70

            =71