Question

Factorise : 64x³ − 729y³
a) (4x + 9y) (16x² − 36xy + 81y²)
b) (4x - 9y) (16x² + 36xy + 81y²)
c) (4x - 9y) (16x² − 36xy + 81y²)
d) (4x + 9y) (16x² + 36xy - 81y²)

Answer 1

Answer:

(4x+9y)(16x²+36xy+81y²)

Step-by-step explanation:

64x³- 729y³ = (4x)³ - (9x)³

using Identity (a³ - b³) = (a+b)(a²+ab+b²)

= (4x+9y){(4x)²+(4x×9y)+(9y)²}

= (4x+9y)(16x²+36xy+81y²)