(1)
:=,
&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;
×
=
,
&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;
x
÷=
÷,
&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;x=
;
(c)
-=1.
&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;0.三6-0.5三x=0.04,
&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1; 0.三6-0.5三x+0.5三x=0.04+0.5三x,
&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1; 0.三6=0.04+0.5三x,
&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1; 0.三6-0.04=0.04+0.5三x-0.04,
&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1; 0.三c=0.5三x,
&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1; 0.三c÷0.5三=0.5三x÷0.5三,
&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1;&nbs1; x=
.