(1)6.7+6X=11.5,
6.7+6X-6.7=11.5-6.7,
6X=4.8,
6X÷6=4.8÷6,
X=0.8;
(2)2.5+7X=4.6,
2.5+7X-2.5=4.6-2.5,
7X=2.1,
7X÷7=2.1÷7,
X=0.3;
(3)9X+X=25,
10X=25,
10X÷10=25÷10,
X=2.5.
(1)6.7+6X=11.5,
6.7+6X-6.7=11.5-6.7,
6X=4.8,
6X÷6=4.8÷6,
X=0.8;
(2)2.5+7X=4.6,
2.5+7X-2.5=4.6-2.5,
7X=2.1,
7X÷7=2.1÷7,
X=0.3;
(3)9X+X=25,
10X=25,
10X÷10=25÷10,
X=2.5.