Respuesta :

[tex]S=\lbrace-\frac{3}{7},\:\frac{3}{7}\rbrace[/tex]

1) Let's start out by rewriting that into the standard form then solve for x this incomplete quadratic equation:

[tex]\begin{gathered} -49x^2+9=0 \\ -49x^2+9-9=0-9 \\ -49x^2=-9 \\ \frac{-49x^2}{-49}=\frac{-9}{-49} \\ x^2=\frac{9}{49} \\ x=\sqrt{\frac{9}{49}},\:x=-\sqrt{\frac{9}{49}} \\ x=\frac{3}{7},\:x=-\frac{3}{7} \end{gathered}[/tex]

Note that there are two roots.