Let $\mathbf{u}=\langle-1,-1\rangle$ Find the Vector V Such That $\mathbf{u} * \mathbf{v}=-6$ And $|\mathbf{v}|=\sqrt{18}$

Let $\mathbf{u}=\langle-1,-1\rangle$ Find the vector v such that $\mathbf{u} * \mathbf{v}=-6$ and $|\mathbf{v}|=\sqrt{18}$