Are the Two Planes Parallel? Justify Your Answer

Short Answer

Are the two planes $\mathbf { r } _ { 1 } ( s , t ) = \langle 1 + s + t , s - t , 1 + 2 s \rangle \text { and } \mathbf { r } _ { 2 } ( s , t ) = \langle 2 + s + 2 t , 3 + t , s + 3 t \rangle$ parallel? Justify your answer.