Answer:
Step-by-step explanation:
(b - c)/b * (b+c)/b Notice how the second fraction is inverted and multiplied. That's how you handle a 4 tier fraction. Here's a simpler example
[tex]\frac{\frac{2}{3} }{\frac{4}{5} } = \frac{2}{3} * \frac{5}{4}[/tex]
What you get with your problem is
(b^2 - c^2)/b^2