Question

Resolva as equações incompletas.

a) x² − 16= 0

b) x² − 25= 0

c) x² − 4= 0

d) − 2 x² + 18= 0

Answer 1

Resposta:

Explicação passo a passo:

$a)$

$x^{2} -16=0$

$x^{2} =16$

$x=\pm\sqrt{16}$

$x=\pm4$

$S=\{-4;4\}$

$b)$

$x^{2} -25=0$

$x^{2} =25$

$x=\pm\sqrt{25}$

$x=\pm5$

$S=\{-5;5\}$

$c)$

$x^{2} -4=0$

$x^{2} =4$

$x=\pm\sqrt{4}$

$x=\pm2$

$S=\{-2;2\}$

$d)$

$-2x^{2} +18=0$

 $2x^{2} =18$

   $x^{2} =18/2$

   $x^{2} =9$

   $x=\pm\sqrt{9}$

   $x=\pm3$

   $S=\{-3;3\}$