Math Help for Section 3.2, Page 116

Common
Error
When solving an equation by applying the Addition or Multiplication
Property of Equality, be sure to apply the same
operation to
each side of the equation. A common error is applying the opposite
operation. For instance, in the following steps, subtracting $3x$
from the left side and adding $3x$ to right side is incorrect.

The correct solution steps are as follows.

  
 $\eqalign{9x + 2=& 8 – 3x
&{\small\color{red}\quad\quad\quad\text{Original equation. }} \cr
9x + 2+{\color{red}3x}=& 8-3x+{\color{red}3x}
&{\small\color{red}\quad\quad\quad\text{Add }3x\text{ to
each side.}} \cr 12x + 2=& 8
&{\small\color{red}\quad\quad\quad\text{Simplify.}} } $