Question

[5^-1 + (2/3)^-2] : (0,19999999 e ai alguém consegui resolver ?

Answer 1

0,1999...(dízima)
$0,199...= \frac{19-1}{90} = \frac{18}{90} = \frac{1}{5}$
logo
$[5^{-1}+( \frac{2}{3} )^{-2} )\div \frac{1}{5}= \\ \\ ( \frac{1}{5} +( \frac{3}{2} )^2)\div \frac{1}{5} = \\ \\ ( \frac{1}{5} + \frac{9}{4} )\div \frac{1}{5}= \\ \\ ( \frac{4+45}{20})\div \frac{1}{5} = \\ \\ \frac{49}{20} \times \frac{5}{1} = \frac{49}{4}$