Question
If $|\vec{a}| = 3$, $|\vec{b}| = 5$, $|\vec{c}| = 4$, and $\vec{a} + \vec{b} + \vec{c} = \vec{0}$, then the value of $(\vec{a} \cdot \vec{b} + \vec{b} \cdot \vec{b} + \vec{c} \cdot \vec{b})$ is equal to:
If $|\vec{a}| = 3$, $|\vec{b}| = 5$, $|\vec{c}| = 4$, and $\vec{a} + \vec{b} + \vec{c} = \vec{0}$, then the value of $(\vec{a} \cdot \vec{b} + \vec{b} \cdot \vec{b} + \vec{c} \cdot \vec{b})$ is equal to: