Resposta:
[tex]x=\frac{-4-\sqrt{30} }{2} ~~ou~~x=\frac{-4+\sqrt{30} }{2}[/tex]
Explicação passo a passo:
-2x² - 8x + 7 = 0
2x + 8x - 7 = 0
[tex]\Delta=b^2-4ac\\\\\Delta=8^2-4.2(-7)\\\\\Delta=64+56\\\\\Delta=120\\\\\Delta=4.30\\\\x=\frac{-b\mp\sqrt{\Delta} }{2a}\\\\x=\frac{-8\mp2\sqrt{30} }{4} \\\\x=\frac{-4\mp\sqrt{30} }{2}[/tex]
