But equation (1) states $3v_2 + v_3 = -4$. This inconsistency implies no solution exists unless $\mathbfd$ is orthogonal to $\mathbfc$. Check $\mathbfd \cdot \mathbfc = (-4)(2) + (5)(-1) + (1)(3) = -8 -5 +3 = -10 - Groen Casting