Question

Resolva as equaçoes do 2 grau incompletas
A]x² - 36=0

B]x² - 36x =0

C] 3x² - 75 =0

D] 75x² - 3 =0

E] 2x² - 800 =0

F] 800x² - 2x =0

Answer 1

$A] x^{2} - 36=0\\\\ x^{2} =36\to \\\\\ x=\pm \sqrt{36} \to \\\\ x= \pm 6\\\\ \\ S=(-6;6)$




$B] x^{2} - 36x =0\\\\ x(x-36)=0\to \\\\ x=0 \\\\ x-36=0\to x=36\\\\\\ S=(0;36)$




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




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




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




$F] 800 x^{2} - 2x =0\\\\ x(800x-2)=0\to \\\\ x=0\\\\ 800x-2=0\to 800x=2\to x= \frac{2}{800} \to x= \frac{1}{400} \\\\\\ S=(0;\frac{1}{400} )$

Espero ter ajudado...