Question

factorise the following 81x³-3y³​

Answer 1

Answer:

3(3x-y)(9x²+3xy+y²)

Step-by-step explanation:

81x³-3y³

= 3(27³-y³)

= 3[ (3x)³- (y)³]

identity = a³-b³ = (a-b)(a²+ab+b²)

= here, a = 3x and b = y

= 3 [ (3x-y)(3x²+3xy+y²) ]

= 3(3x-y)(9x²+3xy+y²)

hope it helpful