Given vec$(u)=[1,0,-1],$vec$(v)=[-4,-3,-2]$ and vec$(w)=[1,1,-2],$ find

$($i$)$ u$-$v $+2$w

$($ii$)$ the angle between vectors $(2u-v)$ and w$-$v$)$

$($iii$)$ a vector which is perpendicular to both w and v

$($iv$)($u$-$v$)$ downward w