求X.6+[0.5×4/5+(23/5−X)×9]÷4=22.

问题描述:

求X.6+[0.5×

4
5
+(2
3
5
−X)×9]÷4=22.

6+[0.5×

4
5
+(2
3
5
-x)×9]÷4=22,
6+[0.5×0.8+(2
3
5
-x)×9]÷4-6=22-6,
[0.5×0.8+(2
3
5
-x)×9]÷4=16,
[0.4+(2
3
5
-x)×9]÷4×4=16×4,
              0.4+(2
3
5
-x)×9=64,
          0.4+(2
3
5
-x)×9-0.4=64-0.4,
                  (2
3
5
-x)×9=63.6,
               (2
3
5
-x)×9÷9=63.6÷9,
                         2
3
5
-x=
106
15

                       2
3
5
-x+x=
106
15
+x,
                       
106
15
+x=2
3
5

                  
106
15
+x-
106
15
=2
3
5
-
106
15

                             x=-4
7
15