First you have to put all of your common numbers together. 4a and 9a go together. You then subtract those because 9 is negative (-9). Then you get -5a. Now move on to your other numbers. You have 26 and 17. 17 is negative as well (-17), so you subtract it from 26. That gives you 9.
Your new equation is -5a + 9 = 26
Now you subtract 9 from both sides. Your positive (+9) will cancel out with your negative (-9). Then subtract it from 26. 9 minus 26 is 17.
Now your equation is -5a = 17
Since it's negative, you're going to add it (5) to both sides.
Your 5's cancel out, and 17 + 5 is 22.
a = 22
22 is the answer
