Use Mathematical Induction to Prove That $$2 \mid \left( n ^ { 2 } + 3 n \right) \text { for all } n \geq 1 \text {. }$$

Use mathematical induction to prove that $$2 \mid \left( n ^ { 2 } + 3 n \right) \text { for all } n \geq 1 \text {. }$$