Chapter 14, Problem 41P

Perform the following additions in rectangular form:

$\begin{array}{l}\text{a}\text{. }\left(4.2+j6.8\right)+\left(7.6+j0.2\right)\hfill \\ \text{b}\text{. }\left(142+j7\right)+\left(9.8+j42\right)+\left(0.1+j0.9\right)\hfill \\ \text{c}\text{. }\left(4\times {10}^{-6}+j76\right)+\left(7.2\times {10}^{-7}-j5\right)\hfill \end{array}$