Question

E essa! 

9x²+8x-1=0

Answer 1

$9x^2+8x-1=0 \\ \\ \Delta=8^2-4.9.(-1)=64+36=100 \\ \\ x=\frac{-8+-\sqrt{100}}{2.9}=\frac{-8+-10}{18} \\ \\ x_1=\frac{-8-10}{18}=-1 \\ \\ x_2=\frac{-8+10}{18}=\frac{2}{18}=\frac{1}{9}$