（1）4x+9.6x=68
          13.6x=68
    13.6x÷13.6=68÷13.6
              x=5
（2）7x-4×0.73=25.08
        7x-2.92=25.08
   7x-2.92+2.92=25.08+2.92
             7x=28    
              x=4