Question

esolva as equaçoes do 2 grau
incompletas



C] 3x² - 75 = 0

D] 75x² - 3 = 0

E] 2x² - 800 =0

Answer 1

$C) 3 x^{2} -75=0\to \\\\3 x^{2} =75\to \\\\ x^{2} = \frac{75}{3} \to\\\\ x^{2} =25\to\\\\ x=\pm \sqrt{25} \to \\\\ x=\pm 5\\\\\\ S= \left \{-5;5 \left \}$





$D) 75 x^{2} -3=0\to \\\\ 75 x^{2} =3\to \\\\ x^{2} = \frac{3}{75} \to\\\\ x^{2} = \frac{1}{25} \to\\\\ x=\pm \sqrt{ \frac{1}{25} } \to \\\\ x=\pm \frac{1}{5} \\\\\\S= \left \{-\frac{1 }{5};\frac{1 }{5} \left \}$





$E) 2 x^{2} -800=0\to \\\\ 2 x^{2} =800\to\\\\ x^{2} = \frac{800}{2} \to\\\\ x^{2} =400\to\\\\ x=\pm \sqrt{400} \to \\\\ x=\pm 20\\\\\\ S= \left \{-20;20 \left \}$