Question

x(1 – 15x) (1 + 15x)

x(x – 15) (x + 15)

x(1 – 15x) (1 – 15x

x(1 + 15x) (1 – 15x)​

Answer 1

$\huge\underline{\sf{ \times Solution \times }}$

$\large\underline{\sf{given \rightarrow factorise \: {x}^{3} - 225x }}$

$\large\underline{\sf{to \: find \rightarrow factorisation}}$

$\large\underline{\sf{ {x}^{3} - 225x }}$

$\implies \large\underline{\sf{take \: x \: common}}$

$\large\underline{\sf{ x({x}^{2} - 225) }}$

$\large\underline{\sf{225 \: can \: be \: written \: as \: {15}^{2} }}$

$\large\underline{\sf{x( {x}^{2} - {15}^{2} )}}$

$\large\underline{\sf{ {a}^{2} - {b}^{2} = (a + b)(a - b)}}$

$\large\underline{\sf{x(x - 15)(x + 15)}}$

Hence the correct option is b.