Hi there!
First we need to remember the following.

Now substitute both of the formulas.

Work out the parenthesis.

And finally collect terms.

~ Hope this helps you!
There is not enough information
Your inequality looks like this:

To get rid of the /6, you need to multiply by 6 as the opposite operation cancels it out. So, all you need to do is multiply both sides by 6 to isolate x.
Therefore: