◆ QUADRATIC EQUATIONS ◆
[tex]given \: expression \: is \: , \: \\ \\ {x}^{2} - 2x - 15 = 0 \\ \\ = {x}^{2} + 3x - 5x - 15 = 0 \\ \\ = x(x + 3) - 5(x + 3) = 0 \\ \\ = (x - 5)(x + 3) = 0 \\ \\ therefore \: , \\ \\ (x - 5) = 0 \: or \: (x + 3) = 0 \\ \\ solving \: , \: we \: get \: , \\ \\ x = 5 \: or \: x = - 3 \: \: \: \: \: ans.[/tex]
