Question

7x²+9x=21

por favor plis☺️​

Answer 1

$x^2+9x=21\quad :\quad x=\frac{-9+\sqrt{669}}{14},\:x=\frac{-9-\sqrt{669}}{14}\quad \left(\mathrm{Decimal}:\quad x=1.20464\dots ,\:x=-2.49035\dots \right)$