Question

x elevado a 2+18x-115=0​

Answer 1

Olá,

$\Delta=b^2-4\times a\times c\\\Delta = 18^2-4\times 1 \times (-115)\\\Delta = 324 +460\\\Delta = 784$

$x = \frac{-b\pm \sqrt{\Delta}}{2\times a} \\\\x = \frac{-18\pm \sqrt{784}}{2\times 1}$

$x = \frac{-18\pm28}{2}\\ \\x' = \frac{-18+28}{2}=\frac{10}{2} =5 \\\\x"= \frac{-18-28}{2} = \frac{-46}{\:\:\:2} = -23$

Portanto, x = {-23, +5}

espero ter ajudado!