Chapter 3 - Equations and Problem Solving - 3.3 - More on Solving Equations and Problem Solving - Problem Set 3.3 - Page 114: 29

$n=-\dfrac{19}{10}$

Using the properties of equality and combining like terms, the value of the variable that satisfies the given equation, $ -7-2n-6n=7n-5n+12 ,$ is \begin{array}{l}\require{cancel} -2n-6n-7n+5n=12+7 \\\\ -10n=19 \\\\ n=\dfrac{19}{-10} \\\\ n=-\dfrac{19}{10} .\end{array}