2. Notice that $H \cong \mathbb{R} \times \{ 0\}$ and so $G/H \cong \frac{ \mathbb{R} \times \mathbb{R} }{ \mathbb{R} \times \{ 0\} } \cong \left( \mathbb{R} / \mathbb{R} \right) \times \left( \mathbb{R} / \{ 0\} \right) \cong \{ 0\} \times \mathbb{R} \cong \mathbb{R}$