Question

Factorise: a² + 4b² - 4ab-9c²

please I need it fastly give me the answer please ​

Answer 1

Answer:

= (a - 2b - 3c) × (a - 2b + 3c)

Step-by-step explanation:

➺ a² + 4b² - 4ab - 9c²

Use a² - 2ab + b² = (a-b)²

➺ (a - 2b)² - 9c²

Use a²-b² = (a-b)(a+b)

➺ (a-2b-3c) × (a-2b+3c)