Question

1+{2+[3·(4+5)-6+7·8]-9}

Answer 1

1+{2+[3x(4+5)-6+7x8]-9}=
=1+[2+(3x9-6+56)-9]
=1+[2+(27-6+56)-9]
=1+[2+(21+56)-9]
=1+(2+77-9)
=1+(79-9)
=1+70
=71

Succes!!

Answer 2

1{2+[3•(4+5)-6+7•8]-9}
1+[2+(12+15-6+7•8]-9]
1+[2+(12+15-6+56]-9]
1+(2+77-9)
1+70=71