1. To solve this, you could just combine the x's and the m's. There are 3 x's, so that'd be 
. Do the same with the m's. 
. So, your final answer would be 
.
2. Let's make this into a proportion. 54:9 can also be written as 54/9. We could reduce that fraction to 6:1. So, she earns 6 dollars every hour. Now, we'd just plug in the amount of hours to know.
I'll do the first one. 
. So, she made 36 dollars in 6 hours. Just do that for the rest of those problems. :)
3. You can plug this into Algebra.Com's solver. ( http://www.algebra.com/services/rendering/simplifier.mpl ) 
Here it is simplified: 
It simplifies to 
 Divide both sides by -5 to get 
.
 :)