Judging from the title, there is 4x+8(2+x)=52.

We get 4x+ 16+8x=52.

If you move items, you get 12x=52- 16.

Get 12x=36.

The left and right sides of the equation are divided by 12 simultaneously.

Get x=3.

That is, three people did it at first, and then five people did it.