Question

equação exponencial 9^x^2+x=81

Answer 1

$9^{ x^{2} + x} = 81\\\\ 9^{ x^{2} + x} = 9^{2}\\\\ x^{2} + x = 2\\\\ x^{2} + x - 2 = 0$

Δ = $1^{2} - 4.1.(-2)$
Δ = $1 + 8$
Δ = $9$

x = $\frac{-1 +-\sqrt{9} }{2.1} = \frac{-1+-3}{2}$

$x^{1} = \frac{-1 + 3}{2} = \frac{2}{2} = 1\\\\ x^{2} = \frac{-1 - 3}{2} = \frac{-4}{2} = -2$

Espero ter ajudado!