Question

6.(2,0) Resolva as equações: a) x² = 49 b) x²-25=0 c) 2x2 - 72=0 d) x2 = 99 - 10x e)-64+4x2=0 4;-4 ​

Answer 1

Resposta:

Explicação passo a passo:

$a)$

$x^{2} =49$

$x=\pm\sqrt{49}$

$x=\pm7$

$S=\{-7;7\}$

$b)$

$x^{2} -25=0$

$x^{2} =25$

$x=\pm\sqrt{25}$

$x=\pm5$

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

$c)$

$2x^{2} -72=0$

$2x^{2} =72$

$x^{2} =72/2$

$x^{2} =36$

$x=\pm\sqrt{36}$

$x=\pm6$

$S=\{-6;6\}$

$d)\:?????$

$e)$

$-64+4x^{2} =0$

$4x^{2} =64$

$x^{2} =64/4$

$x^{2} =16$

$x=\pm\sqrt{16}$

$x=\pm4$

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