Question

3x²+9=36 equação de segundo grau

Answer 1

$3x^2+9=36\to \\\\\\ 3x^2=36-9\to \\\\ 3x^2=27\to \\\\ x^{2} = \frac{27}{3} \to\\\\ x^{2} =9 \to \\\\x= \sqrt{9} \to \\\\ x=3$