Question

pick a number . multiply the number by 12 and add 6to the product, divide the sum by 3, subtract twice the original numbers and subtract 2.

Answer 1

Let $n$ denotes the picked number. Then we get

$\frac{12n+6}3-2n-2,$

which is equal to

$4n+2-2n-2=2n$ .

We conclude that we get the number which is equal twice to the original number.