Tính bằng hai cách

Tính bằng hai cách :
          a)       826,7 – (426,7 + 150)                         826,7 – (426,7 + 150)
                   ........................................                    ........................................
                   ........................................                    ........................................
                   ........................................                    ........................................
          b)       91,05 – 42,3 – 17,7                            91,05 – 42,3 – 17,7
                   ........................................          ........................................
                   ........................................          ........................................
                   ........................................          ........................................
HELP ME. HUHUHU