Answer :

Let's simplify the expression step-by-step:

[tex]\[ 2 w^3 x^{-6} \cdot 4 u x^2 \cdot 9 u^{-2} w^5 \][/tex]

1. Combine the coefficients:
- Multiply the numerical coefficients: [tex]\(2 \cdot 4 \cdot 9 = 72\)[/tex].

2. Combine the exponents for each variable:
- For [tex]\(w\)[/tex]:
[tex]\[ w^3 \cdot w^5 = w^{3+5} = w^8 \][/tex]
- For [tex]\(x\)[/tex]:
[tex]\[ x^{-6} \cdot x^2 = x^{-6+2} = x^{-4} \][/tex]
- For [tex]\(u\)[/tex]:
[tex]\[ u \cdot u^{-2} = u^{1 + (-2)} = u^{1-2} = u^{-1} \][/tex]

3. Express the final answer with positive exponents:
- [tex]\(x^{-4}\)[/tex] remains as [tex]\(x^{-4}\)[/tex] since we can include negative exponents.
- [tex]\(u^{-1}\)[/tex] remains as [tex]\(u^{-1}\)[/tex] since we can include negative exponents.

Putting it all together, the simplified expression is:

[tex]\[ 72 w^8 x^{-4} u^{-1} \][/tex]