I'm pretty sure you are asking for the value of b. Let's actually write it and then solve it:

Solving for b yields:

So,
b = 19.59. If you want the answer in simplified radical form, we can also do that:

So,
b = 8√6 = 19.59
PLEASE give a picture so we know what your talk about........
2.36 repeating
THIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIISSSSSSSSSSSSSSSSSS IS THE ANSWER!
Look at the table for each type of bird. 5x=15. 6x=18. 10x=30. What would you multiply each of those by to get your answer and find the difference? 5x=15; x= 3. It is the same for each number. So the difference is by 3. I think if I understand this correctly, that would be how you do it. Does this help?