## Thinking Mathematically (6th Edition)

To solve a variable in a problem to get a value which is satisfied the equation of a problem. The variable is anything for example $2x+3=5$solve the variable. It means to find the value of $x$which satisfied the given equation i.e. \begin{align} & 2x+3=5 \\ & 2x=2 \\ & x=1 \end{align} It means$x=1$ satisfied the equation $2x+3=5$,then, \begin{align} & 2x+3=2\left( 1 \right)+3 \\ & =5 \end{align} Hence, both are same. It means$x=1$ and it’s any unknown variable which is required to solve the problem and to get the solution.