(1)30-3.5x=16,
30-3.5x+3.5x-16=16+3.5x-16,
14=3.5x,
3.5x=14,
3.5x÷3.5=14÷3.5,
x=4,
(2)
1
4 :2=4x:32,
8x=32×
1
4 ,
8x÷8=8÷8,
x=1.
(3)60%:
1
2 =
2x
5 ,
60%:
1
2 =2x:5,
1
2 ×2x=0.6×5,
x=3.
(1)30-3.5x=16,
30-3.5x+3.5x-16=16+3.5x-16,
14=3.5x,
3.5x=14,
3.5x÷3.5=14÷3.5,
x=4,
(2)
1
4 :2=4x:32,
8x=32×
1
4 ,
8x÷8=8÷8,
x=1.
(3)60%:
1
2 =
2x
5 ,
60%:
1
2 =2x:5,
1
2 ×2x=0.6×5,
x=3.