(1)[2/3]X-[1/2]X=42,
[1/6]x=42,
[1/6]x÷
1
6=42÷
1
6,
x=252;
(2)[3/4]:X=3:12,
3x=[3/4]×12,
3x÷3=9÷3,
x=3;
(3)4X-1.6X=24,
2.4x=24,
2.4x÷2.4=24÷2.4,
x=10;
(4)7x+4=11,
7x+4-4=11-4,
7x=7,
7x÷7=7÷7,
x=1.
(1)[2/3]X-[1/2]X=42,
[1/6]x=42,
[1/6]x÷
1
6=42÷
1
6,
x=252;
(2)[3/4]:X=3:12,
3x=[3/4]×12,
3x÷3=9÷3,
x=3;
(3)4X-1.6X=24,
2.4x=24,
2.4x÷2.4=24÷2.4,
x=10;
(4)7x+4=11,
7x+4-4=11-4,
7x=7,
7x÷7=7÷7,
x=1.