Question

Resolva a equação x+ x/3 + x/9 +... = 9


Podem me ajudar??

Answer 1

Temos uma pg infinita onde:

$a_1=x\\\\q=\dfrac13\\\\S_\infty=\dfrac{a_1}{1-q}\\\\\dfrac{a_1}{1-q}=9\\\\\dfrac{x}{1-\frac13}=9\\\\x=9-3\\\\x=6$