The expression in the image is:

$\frac{3a^4}{c^2} - 6a$

Would you like a detailed explanation on how to simplify or solve this expression, or do you have a specific question about it?

Here are five related questions you might find useful:

1. How do you factor expressions with exponents like $a^4$?
2. What are the steps to combine terms in algebraic expressions?
3. How would the expression change if $c = 1$?
4. How can you find the roots of the expression set to zero?
5. What is the significance of the variable $c$ in the expression?

Tip: Always look for common factors in algebraic expressions to simplify them before solving or further manipulating the equation.