Correct the mistakes in the following questions.
1. 1/3x -1 =4 2. 2 = 2x +1
x-1=12 1 = 2x
x=13 x = 2
3. 2(x-5)=12 4. 3x-2/3 =4
2x-5=12 x-2=4
x=17/2 x=6