(1)12X-3.4=8,
12X-3.4+3.4=8+3.4,
12X=11.4,
12X÷12=11.4÷12,
X=0.95;
(2)2X=3.6,
2X÷2=3.6÷2,
X=1.8;
(3)X÷1.1=3.6,
X÷1.1×1.1=3.6×1.1,
X=3.96;
(4)X+6=14.4,
X+6-6=14.4-6,
X=8.4.
(1)12X-3.4=8,
12X-3.4+3.4=8+3.4,
12X=11.4,
12X÷12=11.4÷12,
X=0.95;
(2)2X=3.6,
2X÷2=3.6÷2,
X=1.8;
(3)X÷1.1=3.6,
X÷1.1×1.1=3.6×1.1,
X=3.96;
(4)X+6=14.4,
X+6-6=14.4-6,
X=8.4.