Question

resolvendo a equação ×+ײ+׳+×⁴+...=21, obtemos para × o valor de :

Answer 1

$x+x^2+x^3+x^4+\cdots =21\\ x+x(x+x^2+x^3+x^4+\cdots)=21\\ x+21x=21\\ 22x=21\\ \\ \boxed{x=\dfrac{21}{22}}$