Question

x ao quadrado menos oitro x mais doze igual a zero

Answer 1

$x^{2} -8x+12=0\\ \ -8^{2} -4.1.12\\64-48=16\\ \frac{-8+- \sqrt[2]{16} }{2.1} \\\\ \frac{-8+-4}{2} \\\\x'= \frac{-8+4}{2}=-2\\\\x''= \frac{-8-4}{2} =-6$