Question

resolva as equaçoes imcompletas

a) x²-36=0

b) x²-36x=0


c) 3x²-75=0

d) 75x²-3=0

e) 2x²-800=0

f) 800x²-2x=0


por fvor gente e pra amanha eu so muito ruim em matematica peço a colaboraçao de todos

Answer 1

a) x² - 36 = 0 => x² = 36 => x = ±√36 => x = ±6

b) x² - 36.x = 0 => x.(x - 36) = 0 => x = 0 ou x - 36 = 0 => x = 36

c) 3.x² - 75 = 0 => 3.x² = 75 => x² = 75/3 => x² = 25 => x = ±√25 => x = ±5

d) 75.x² - 3 = 0 => 75.x² = 3 => x² = 3/75 => x² = 1/25 => x = ±√(1/25) => x = ±1/5

e) 2.x² - 800 = 0 => 2.x² = 800 => x² = 800/2 => x² = 400 => x = ±√400 => x = ±20

f) 800.x² - 2.x = 0 => 2.x.(400.x - 1) => 2.x = 0 => x = 0 ou 400.x - 1 = 0 => 400.x = 1 => x = 1/400

Answer 2

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





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





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





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





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





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