Question

2x² - 8 = 0 Qual a resposta me ajudem pfvr <3

3z² - 70 = 5

Answer 1

Resposta:

$2x^2-8=0\\ 2x^2=8\\ x^2=8\div2\\ x^{2} =4\\ \\ x=\pm\sqrt{4} \\ x=\pm2\\ \\ S=\{-2,+2\}\\ ----------------\\ 3z^2-70=5\\ 3z^2=5+70\\ 3z^2=75\\ z^2=75\div3\\ z^2=25\\ \\ z=\pm\sqrt{25} \\ \\ z=\pm5\\ \\ S=\{-5,+5\}$