Chapter 6.7, Problem 8MRE

To determine

To Solve:

  $5\left|n\right|-7=3$

Answer to Problem 8MRE

  $n=\pm 2$

Explanation of Solution

Given :

The equation is :

  $5\left|n\right|-7=3$

Calculation:

Given:

  $\begin{array}{l}5\left|n\right|-7=3\\ \Rightarrow 5n-7=3\text{ and }-5n-7=\mathrm{3.............................}[\left|x\right|=\pm x]\\ \Rightarrow 5n-7+7=3+7\text{ and }-5n-7+7=3+\mathrm{7.......}[\text{add 7 each side]}\\ \Rightarrow 5n=10\text{ and }-5n=10\\ \Rightarrow \frac{5n}{5}=\frac{10}{5}\text{ and }\frac{-5n}{5}=\frac{10}{5}\mathrm{..................................}[\text{divide each side by 5]}\\ \Rightarrow n=2\text{ and }n=-2\\ \Rightarrow n=\pm 2\end{array}$