Question

$(a + b)3$
identities​

Answer 1

An identity is an equality which is true for all variables.

Identities are true for all value of a and b.

Identities are used in simplifying, evaluating and factorizing algebraic expression.

$\bold{(a + b) ^{3} = {a}^{3} + {b}^{3} + 3ab(a + b)}$

$(a - b) ^{3} = {a}^{3} - {b}^{3} + 3ab(a - b)$

${a}^{3} + {b}^{3} = (a + b)( {a}^{2} - ab + {b}^{2} )$

${a}^{3} - {b}^{3} = (a - b)( {a}^{2} + ab + {b}^{2} )$

$(a + b + c) ^{2} = {a}^{2} + {b}^{2} + {c}^{2} + 2ab + 2bc + 2ca$

${a}^{3} + {b}^{3} + {c}^{3} - 3abc = (a + b + c)( {a}^{2} + {b}^{2} + {c}^{2} - ab - bc - ca)$