Let's simplify the given expression step by step:

Given expression: $-2 + 6y^3 - 2y^3 + 7 - 7 + 6x^2 - 2x^2$

1. Combine like terms:

   • Combine the $y^3$ terms: $6y^3 - 2y^3 = 4y^3$.
   • Combine the $x^2$ terms: $6x^2 - 2x^2 = 4x^2$.
   • Combine the constant terms: $-2 + 7 - 7 = -2$.

2. Simplified expression: $4y^3 + 4x^2 - 2$

So, the simplified expression is: $4y^3 + 4x^2 - 2$

Would you like to explore more details or have any questions?

Here are 5 related questions to consider:

1. What is the process for identifying and combining like terms in an expression?
2. How would the expression change if the coefficients of $x^2$ and $y^3$ were altered?
3. Can the simplified expression be factored further?
4. What is the degree of the polynomial in the simplified expression?
5. How would this expression be graphed in a 3D coordinate system?

Tip: Always organize and combine like terms systematically to avoid mistakes when simplifying expressions.