Answer
$a_1=-2$
$a_2=2$
$a_3=-\frac{8}{3}$
$a_4=4$
$a_{10}=\frac{512}{5}$
Work Step by Step
We are given:
$a_{n}=(-1)^{n} \frac{2^{n}}{n}$
We evaluate:
$a_1=(-1)^{1} \frac{2^{1}}{1}=-1*2=-2$
$a_2=(-1)^{2} \frac{2^{2}}{2}=1*4/2=2$
$a_3=(-1)^{3} \frac{2^{3}}{3}=-1*8/3=-\frac{8}{3}$
$a_4=(-1)^{4} \frac{2^{4}}{4}=1*16/4=4$
$a_{10}=(-1)^{10} \frac{2^{10}}{10}=\frac{1024}{10}=\frac{512}{5}$