Multiply: (21m + 3m2) and (3lm – 5m2)

1.	Multiply: (21m + 3m2) and (3lm – 5m2)
Answer» (2lm + 3m²) and (3lm – 5m²) = 2lm (3lm – 5m²) + 3m² (3lm – 5m²) = 2lm × 3lm – 2lm × 5m² + 3m² × 3lm – 3m² × 5m² = (2 × 3) l²m² – (2 × 5) lm³ + (3 × 3) lm³ – (3 × 5) m⁴ = 6l2m² – 10lm³ + 9lm³ – 15m⁴ = 6l2m² – lm³ – 15m⁴

Answer»

(2lm + 3m²) and (3lm – 5m²)

= 2lm (3lm – 5m²) + 3m² (3lm – 5m²)

= 2lm × 3lm – 2lm × 5m² + 3m² × 3lm – 3m² × 5m²

= (2 × 3) l²m² – (2 × 5) lm³ + (3 × 3) lm³ – (3 × 5) m⁴

= 6l2m² – 10lm³ + 9lm³ – 15m⁴

= 6l2m² – lm³ – 15m⁴

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