По столбикам (45-42.6)*3.3+9:7.5=

1) 45-42,6=2.4 2)2.4*3.3=7.92 3) 9:7.5=1.2 4)7.92+1.2=9.12

   45                        2.4           90   :  7.5                        7.92  - 42,6                   *3.3           75   -----------               +  1.2 ---------              -----------     -----------  1.2             -----------------      2.4                     72           150                                  9.12                              72             150                        --------------   ----------                             7.92               0