Question

3x ao quadrado +147=0 sem usar baskara

Answer 1

$3 x^{2} +147=0\to\\\\ 3 x^{2} =-147\to\\\\ x^{2} =- \dfrac{147}{3} \to\\\\ x^{2}= -49\to\\\\x=\pm~ \sqrt{-49} \to\\\\\\N\~ao~~tem~~rai\´zes~~dentro~~dos~~reais,~~mas~~tem~~nos~~complexos;$



$Sendo :~~\sqrt{-1} =i\\\\x=\pm~ \sqrt{-1\times49} \to\\\\ x=\pm~ \sqrt{-1}\times \sqrt{49} \to \\\\ x=\pm~i\times7\to\\\\ x=\pm~7i \\\\\\ \large\boxed{\boxed{S=\{-7i~;~7i\}}}$