Chapter 3.1, Problem 9E

To determine

To find:

The solution of the equation and check the solution.

Answer to Problem 9E

The solution for the equation $13n+42=81$ is $n=3$ .

Explanation of Solution

Given information:

Consider, the equation $13n+42=81$

From the provided expression find the value of $n$ .

Therefore,

  $\begin{array}{l}13n+42=81\\ 13n=81-42\\ 13n=39\\ n=\frac{39}{13}\\ n=3\end{array}$

The value of $n$ is $3$ .

Now, to check the solution, substitute the value of $n$ in the provided expression.

Therefore,

  $\begin{array}{l}13\left(3\right)+42=81\\ 13\left(3\right)=81-42\\ 13\left(3\right)=39\\ 3=\frac{39}{13}\\ 3=3\end{array}$

As left hand side is equal to right hand side, this signifies that the solution is correct.