Question

LCM of x3 – 9x and x2

– 2x – 3 is

Answer 1

${x}^{3} - 9x = x( {x}^{2} - 9) \\ x(x - 3)(x - 3) \\ ( \: {a}^{2} - {b}^{2} ) = (a + b)(a - b) \\ second \: expression \\ {x}^{2} - 2x - 3 = {x}^{2} - 3x + x - 3 = 0 \\ x(x - 3) + (x - 3) \\ (x + 1)(x - 3) \\hence \: the \: lcm \: is \: \\ x(x - 3)(x + 1)$