Verify the identity {a}^{3} + {b}^{3} = ( {a}^{2} – ab \: + {b}^{2} )a3+b3=(a2−ab+b2) Please answer in steps please About the author Madeline
Answer: Proof of a³ + b³ = (a + b)(a² – ab + b²) you know that, (a + b)³ = a³ + 3ab(a + b) + b³ then a³ + b³ = (a + b)³ – 3ab(a + b) = (a + b)[(a + b)² – 3ab] = (a + b)(a² + 2ab + b² – 3ab) = (a + b)(a² – ab + b² ) Reply
Answer:
Proof of a³ + b³ = (a + b)(a² – ab + b²)
you know that,
(a + b)³ = a³ + 3ab(a + b) + b³
then
a³ + b³ = (a + b)³ – 3ab(a + b)
= (a + b)[(a + b)² – 3ab]
= (a + b)(a² + 2ab + b² – 3ab)
= (a + b)(a² – ab + b² )