$\text{Đáp án + Giải thích các bước giải:}$
$x-\dfrac{8-\dfrac{8}{5}+\dfrac{8}{25}-\dfrac{8}{125}}{9-\dfrac{9}{5}+\dfrac{9}{25}-\dfrac{9}{125}} : \dfrac{161616}{151515} = \dfrac{4+\dfrac{4}{73}-\dfrac{4}{115}}{5+\dfrac{5}{73}-\dfrac{1}{23}}$
$x-\dfrac{8-\dfrac{8}{5}+\dfrac{8}{25}-\dfrac{8}{125}}{9-\dfrac{9}{5}+\dfrac{9}{25}-\dfrac{9}{125}} : \dfrac{161616}{151515} = \dfrac{4+\dfrac{4}{73}-\dfrac{4}{115}}{5+\dfrac{5}{73}-\dfrac{5}{115}}$
$⇔x-\dfrac{8(1-\dfrac{1}{5}+\dfrac{1}{25}-\dfrac{1}{125})}{9(1-\dfrac{1}{5}+\dfrac{1}{25}-\dfrac{1}{125})}:\dfrac{16}{15}=\dfrac{4(1+\dfrac{1}{73}-\dfrac{1}{115})}{5(1+\dfrac{1}{73}-\dfrac{1}{115})}$
$⇔x-\dfrac{8}{9}.\dfrac{15}{16}=\dfrac{4}{5}$
$⇔x-\dfrac{5}{6}=\dfrac{4}{5}$
$⇔x=\dfrac{4}{5}+\dfrac{5}{6}$
$⇔x=\dfrac{24}{30}+\dfrac{25}{30}$
$⇔x=\dfrac{49}{30}$
Vậy $x=\dfrac{49}{30}$
$#minosuke$
