Answer
$-3 i+2j -k$
Work Step by Step
Suppose two vectors $P_1=\lt 2,9,-2 \gt$ and $P_2=\lt 5,7,-1 \gt $. Need to find $\overrightarrow{P_1P_2}$ as follows:
$\overrightarrow{P_1P_2}=\overrightarrow{P_2}-\overrightarrow{P_1}$
or, $=\lt 2,9,-2 \gt -\lt 5,7,-1 \gt$
or, $ =\lt -3,2,-1 \gt$
In vector form we have $\overrightarrow{P_1P_2}=-3 i+2j -k$