The perimeter of a regular hexagon is 42a + 18.
Write an expression for the length of one of its sides.
![The perimeter of a regular hexagon is 42a 18 Write an expression for the length of one of its sides class=](https://us-static.z-dn.net/files/d66/4f0678fc4e4a9698ad00125d1159bd1d.png)