Question

1+{2+[3•(4+5)-6+7•8]-9}=

Answer 1

1+{2+[3·9-6+7·8]-9}=
1+(2+77-9)=
1+70 =71

Answer 2

1+[2+(3*9-6+7*8)-9]= 1+[2+(27-6+57)-9]= 1+[2+(21+57)-9]= 1+(2+78-9)= 1+(80-9)= 1+78= 79