Question

qual a raiz(zero) de ✓x²-9?​

Answer 1

$\sqrt{ {x}^{2} - 9 } = 0 \\ ({ \sqrt{ {x}^{2} - 9 } })^{2} = {0}^{2} \\ {x}^{2} - 9 = 0 \\ {x}^{2} = 9 \\ x = 3 \: ou \: x = - 3$