Question

$(3^x)^{x} { + }^{1} = 729$
qual a resposta?

Answer 1

$(3^x)^{x+1}=729$

$(3^{x.(x + 1)} = 729$

$3^{x^2+x}=729$

$3^{x^2+x}=3^6$

x² + x = 6
x² + x - 6 = 0

Δ = b² - 4.a.c 
Δ = 1² - 4 . 1 . -6 
Δ = 1 - 4. 1 . -6 
Δ = 25

Há 2 raízes reais.

x = (-b +- √Δ)/2a

x' = (-1 + √25)/2.1   
x'' = (-1 - √25)/2.1

x' = 4 / 2   
x'' = -6 / 2

x' = 2   
x'' = -3

S = {-3, 2}