Problem $3$:

The pipe assembly is subjected to three forces of $,$

$-4\mathrm{.}00$ kip, and $F_3=\{-3\mathrm{.}00,0,0\}$ kip. Determine the sum of the moment of the forces $1)$ about $x$

axis $($the unit vector of $x$ is $i)$ and $2)$ about line AC$.$ Express the result as a Cartesian vector.