Answer :

To simplify the expression [tex]\(\left(-8 p^3 - 11 p^2 q \right) + \left(p q^2 - 5 q^3 \right) - \left(-6 p^2 q + p q^2 \right)\)[/tex], let's break it down step by step:

1. Write out the expression:
[tex]\[ \left(-8 p^3 - 11 p^2 q \right) + \left(p q^2 - 5 q^3 \right) - \left(-6 p^2 q + p q^2 \right) \][/tex]

2. Distribute the negative sign through the third term:
[tex]\[ -\left(-6 p^2 q + p q^2 \right) = 6 p^2 q - p q^2 \][/tex]

Now the expression is:
[tex]\[ \left(-8 p^3 - 11 p^2 q \right) + \left(p q^2 - 5 q^3 \right) + \left(6 p^2 q - p q^2 \right) \][/tex]

3. Combine like terms:

- For [tex]\(p^3\)[/tex]:
[tex]\[ -8 p^3 \][/tex]

- For [tex]\(p^2 q\)[/tex]:
[tex]\[ -11 p^2 q + 6 p^2 q = -5 p^2 q \][/tex]

- For [tex]\(p q^2\)[/tex]:
[tex]\[ p q^2 - p q^2 = 0 \][/tex]

- For [tex]\(q^3\)[/tex]:
[tex]\[ -5 q^3 \][/tex]

4. Putting it all together:
[tex]\[ -8 p^3 - 5 p^2 q + 0 - 5 q^3 \][/tex]

Simplify by removing the zero term:
[tex]\[ -8 p^3 - 5 p^2 q - 5 q^3 \][/tex]

So, the simplified expression is:
[tex]\[ -8 p^3 - 5 p^2 q - 5 q^3 \][/tex]