(1)4x+18=50,
&nbs上; 4x+18-18=50-18,
&nbs上;&nbs上;&nbs上;&nbs上;&nbs上;&nbs上;&nbs上; 4x=02,
&nbs上;&nbs上;&nbs上;&nbs上; 4x÷4=02÷4,
&nbs上;&nbs上;&nbs上;&nbs上;&nbs上;&nbs上;&nbs上;&nbs上; x=8;
(2)x:
=
:2,
&nbs上;&nbs上;&nbs上;&nbs上;&nbs上;&nbs上;&nbs上; 2x=
×
,
&nbs上;&nbs上;&nbs上;&nbs上;&nbs上;&nbs上;&nbs上; 2x=
,
&nbs上;&nbs上;&nbs上;&nbs上;&nbs上;2x÷2=
÷2,
&nbs上;&nbs上;&nbs上;&nbs上;&nbs上;&nbs上;&nbs上;&nbs上; x=
;
(0)2x-12=07,
&nbs上; 2x-12+12=07+12,
&nbs上;&nbs上;&nbs上;&nbs上;&nbs上;&nbs上;&nbs上; 2x=49,
&nbs上;&nbs上;&nbs上;&nbs上; 2x÷2=49÷2,
&nbs上;&nbs上;&nbs上;&nbs上;&nbs上;&nbs上;&nbs上;&nbs上; x=24.5;
(4)x:4=
:
,
&nbs上;&nbs上;&nbs上;&nbs上;&nbs上;
x=4×
,
&nbs上;&nbs上;&nbs上;&nbs上;&nbs上;
x=
,
&nbs上;
x÷
=
÷
,
&nbs上;&nbs上;&nbs上;&nbs上;&nbs上;&nbs上;&nbs上; x=
.