Question

Expand (2x – /3 )3 using suitable identity.

Answer 1

Question,

Expand (2x – 3)³ using suitable identity.

Answer,

8x³-36x² + 54x - 27

Solution,

$by \: using \: the \: idenity \: \\ {( a - b)}^{3} = {a}^{3} - {b}^{3} - 3ab(a - b) \\ = > {(2x - 3)}^{3} = {(2x)}^{3} - {(3)}^{3} - 3(2x)(3)(2x - 3) \\ = > {8x}^{3} - 27 - 18x (2x - 3) \\ = > {8x}^{3} - 27 - 36 {x}^{2} + 54x \\ = > {8x}^{3} - 36x ^{2} + 54x - 27$

Hope it helps :)