Question

factorise:- 81-16x² ​

Answer 1

Step-by-step explanation:

Rewrite 81 as 92 . Rewrite 16x2 16 x 2 as (4x)2 ( 4 x ) 2 . Since both terms are perfect squares, factor using the difference of squares formula, a2−b2=(a+b)(a−b) a 2 - b 2 = ( a + b ) ( a - b ) where a=9 and b=4x b = 4 x . Multiply 4 by −1 .

Answer 2

Answer:

   (9 - 4x) (9 + 4x)

Step-by-step explanation:

81 - 16x² ​

= (9)² - (4x)²

a² - b² = (a + b) (a - b)

= (9 - 4x) (9 + 4x)