Question

Factorise the algebraic expression (7a2 - 63b2)

Answer 1

Answer:

7 (a + 3b) (a - 3b)

Step-by-step explanation:

7a^2 - 63b^2

7 (a^2 - 9b^2)         [taking 7 out as common in both the terms]

7 (a^2 - (3b)^2)        [It is of the form a^2 - b^2]

7 (a + 3b) (a - 3b)     [ a^2 - b^2 = (a+b) (a-b)]

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