解方程. 11.8-2x=4
0.5:
5.25x-18=
|
(1)11.8-2x=4
,4 5
11.8-2x+2x=4
+2x,4 5
2x+4
=11.8,4 5
2x+4
-44 5
=11.8-44 5
,4 5
2x=7,
2x÷2=7÷2,
x=3.5;
(2)0.5:
=1 4
:x,2 3
0.5x=
×1 4
,2 3
0.5x=
,1 6
0.5x÷0.5=
÷0.5,1 6
x=
;1 3
(3)5.25x-18=
x,3 4
5.25x-18-
x=3 4
x-3 4
x,3 4
4.5x-18=0,
4.5x-18+18=0+18,
4.5x=18,
4.5x÷4.5=18÷4.5,
x=4.