simplify each expression:

1. (–3x)² (x–³) (3x⁵)
2. (2y)³ (–2x–¹)² (3y⁴)
3. (–a²³) (–a⁶³) (–a–¹⁶)
4. (–b³²) (–b–⁴⁰) (–b–⁹)–³
5. (5b³) (–2b)³
6. (3m⁵) (–2m²)⁴
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