Question

Factorise the following
(i) x2 - 36
(iv) 81 - 64x2
(vii) x2-81
x (p² – 20q+q) – r
(ii) 49x? – 25y?
(v) x+y+ - 64
(viti 2x - 32 x
(xi) (x + y)2 – (x - y)?
(ii) m - 121
(vi) 6x² – 54
(ix) 81x – 121x²​

Answer 1

Answer:

1) x^2 - 36

= (x) ^2 - (6) ^2

= ( x - 6 ) ( x + 6 ) { (a)^2 - (b)^2 = (a+b)(a-b) }

2) 81 - 64x^2

= (9) ^2 - (8x) ^2

= ( 9 - 8x ) ( 9 + 8x ) { (a)^2 - (b)^2 = (a+b)(a-b) }

3) x^2 - 81

= (x) ^2 - (9) ^ 2

= ( x - 9 ) ( x + 9 )

4) 49x^2 - 25x^2

= ( 7x ) ^2 - ( 5x ) ^2

= (7x -5x) ( 7x +5x)

= 2x × 12x = 24x^2