Let's look at the first one:

First step, subtract three from both sides of the inequality using the rule:

"An equal quantity may be added to, (or subtracted from) both sides of an inequality without changing the inequality"

Now we have to multiply both sides by 3 using the rule:

"An equal positive quantity may multiply (or divide) both sides of an inequality without changing the inequality."

Using the same rule above, we have to divide by 2 to isolate x:

And there you go.

Another IMPORTANT rule is this:

"If both sides of an inequality are multiplied (or divided) by a negative quantity then the inequality is reversed"

I think you can solve the other two.