Question

[20•(840-208•4)-500]+123•9

Answer 1

(20x(840-832)-500)+123x9=
(20x8-500)+123x9=
160-500+1107=
-340+1107=767

Answer 2

[20•(840-208•4)-500]+123•9=
=[20•(840-832)-500]+1107=
=(20•8-500)+1107=
=(160-500)+1107=
=-340+1107=
=767