Given \(\mathbf u=(2,-1,4)\) and \(\mathbf v=(5,3,-2)\), compute \(\mathbf u+\mathbf v\).

Given \(\mathbf a=(1,-3,2)\), compute \(-4\mathbf a\).

For \(\mathbf u=(3,1,-2)\) and \(\mathbf v=(-1,4,5)\), compute \(2\mathbf u-3\mathbf v\).

Find \(x\) and \(y\) if \((x,2,y)+3(1,-1,4)=(5,-1,14)\).