Question

me ajudem nessa, por favor

Answer 1

$y = y_{0} .2 ^{-0,5t} \\ \frac{ y_{0}}{2} = y_{0} . 2^{-0,5t} \\ \frac{ \frac{y0}{2}}{yo} =2. ^{-0,5t} \\ \frac{1}{2} =2. ^{-0,5t} \\ log \frac{1}{2}=log 2^{-0,5t} \\ log \frac{1}{2} = -0,5t.log 2 \\ -0,3010 = -0,5t.0,3010 \\ -1= -0,5t \\ 0,5t = 1 \\ t = \frac{1}{0,5} \\ t = 2 horas$

Espero ter ajudado