解方程. x×(1−4/9)=5/6 x+7/9x=2 11x-50%=16 (x+2/7)×40%=8.

问题描述:

解方程.
x×(1−

4
9
)=
5
6

x+
7
9
x=2

11x-50%=16
(x+
2
7
)×40%=8.

(1)x×(1-

4
9
)=
5
6

               
5
9
x=
5
6

            
5
9
9
5
=
5
6
×
9
5

                 x=
3
2

(2)x+
7
9
x=2,
     
16
9
x=2,
 
16
9
9
16
=2×
9
16

         x=
9
8

(3)11x-50%=16
 11x-50%+50%=16+50%,
         11x=16.5,
     11x÷11=16.5÷11,
           x=1.5;
(4)(x+
2
7
)×40%=8,
(x+
2
7
)×40%÷40%=8÷40%,
             x+
2
7
=20,
          x+
2
7
-
2
7
=20-
2
7

               x=19
5
7