Answer
$\dfrac{-3}{2},\dfrac{4}{3},\dfrac{-5}{4}, \dfrac{6}{5}$
Work Step by Step
Need to find the first four terms of $a_n=(-1)^n\dfrac{n+2}{n+1}$ when $n=1,2,3,4$
Thus,
$a_1=(-1)^1(\dfrac{1+2}{1+1})=\dfrac{-3}{2}$
$a_2=(-1)^2(\dfrac{2+2}{2+1})=\dfrac{4}{3}$
$a_3=(-1)^3(\dfrac{3+2}{3+1})=\dfrac{-5}{4}$
$a_4=(-1)^4(\dfrac{4+2}{4+1})=\dfrac{6}{5}$
Hence, the first four terms are: $\dfrac{-3}{2},\dfrac{4}{3},\dfrac{-5}{4}, \dfrac{6}{5}$
