Question

Factorise:
8x'3+y'3+27z'3-18xyz​

Answer 1

Factorise: 8x³ + y³ + 27z³ - 18xyz

Solution:

➨ 8x³ + y³ + 27z³ - 18xyz

➨ (2x)³ + y³ + (3z)³ - 3 × (2x) × y × (3z)

➨ a³ + b³ + c³ - 3abc

where 2x = a , y = b and 3z = c

➨ (a+b+c) (a² + b² + c² - ab - bc - ca)

➨ (2x + y + 3z) ( 4x² + y² + 9z² - 2xy - 3yz - 6xz)

Extra Dose:

• (a + b)³ = a³ + b³ + 3ab (a+b)

• (a - b)³ = a³ - b³ - 3ab (a-b)

Thanks