Chapter 11.3, Problem 2QCE

Suppose that u, v, and w are vector in 3-space such that $‖\text{u}‖=5,\text{u}\cdot \text{v}=7,\text{and}\text{u}\cdot \text{w}=-3.$

$\begin{array}{l}\left(\text{a}\right)\text{u}\cdot \text{u}=\_\_\_\_\_\_\_\\ \left(\text{b}\right)\text{v}\cdot \text{u}=\_\_\_\_\_\_\_\\ \left(\text{c}\right)\text{u}\cdot \left(\text{v}-\text{w}\right)=\_\_\_\_\_\_\_\\ \left(\text{d}\right)\text{u}\cdot \left(2\text{w}\right)=\_\_\_\_\_\_\_\_\end{array}$