(7a2 – 63b2) = ?(i) (7a – 9b) (9a + 7b)(ii) (7a – 9b) (7a + 9b)

1.	(7a2 – 63b2) = ?(i) (7a – 9b) (9a + 7b)(ii) (7a – 9b) (7a + 9b)(iii) 9(a – 3b) (a + 3b)(iv) 7(a – 3b) (a + 3b)
Answer» (iv) 7(a – 3b) (a + 3b) let us consider (7a² – 63b²) = 7(a² – 9b²) by taking 7 as the common factor By using the formula a² – b² = (a – b) (a + b) = 7 (a – 3b) (a + 3b)

(7a2 – 63b2) = ?(i) (7a – 9b) (9a + 7b)(ii) (7a – 9b) (7a + 9b)(iii) 9(a – 3b) (a + 3b)(iv) 7(a – 3b) (a + 3b)

Answer»

(iv) 7(a – 3b) (a + 3b)

let us consider (7a² – 63b²) = 7(a² – 9b²) by taking 7 as the common factor

By using the formula a² – b² = (a – b) (a + b)

= 7 (a – 3b) (a + 3b)