（1）4x+3.2x=36

              7.2x=36

                   x=5（2）3.2x-1.6= 4.8

               3.2x=6.4

                    x=2

（3）（1+0.32）x=6.6

                   1.32x=6.6

                         x=5（4）x-18=24×0.2

         x-18=4.8

              x=22.8

（5）4×2.5+3x=31

               10+3x=31

                      x=7（6）4.6x-8.7=17.98

              4.6x=9.28

                   x=5.8

（7）3.7x+6.5x=1.02

               11.2x=1.02

                     x=0.1（8）0.6×（3+x）=12

                        3+x=20

                            x=17