Question

Algebra Basics Solve the equation. Check your solution. (Lesson 3.2)

$\mathbf{3}(\mathbf{x}\mathbf{+}\mathbf{4})\mathbf{=}\mathbf{9}$

Short answer

The solution for the equation$3(x+4)=9$ is$x=-1$ .

Step-by-step solution

– Separate the variable and constants

Write the original equation and separate the variables.

$\begin{array}{c}3(x+4)=9\\ 3x+12=9\\ 3x=9-12\\ 3x=-3\end{array}$

– Solve for x

Now, divide both sides of the equation by 3.

$\begin{array}{c}x=\frac{-3}{3}\\ x=-1\end{array}$

Therefore, the solution of the equation is$x=-1$ .

– Check the solution 

To check the solution, write the original equation and substitute the value of x.

$3(x+4)=9$

Now, substitute$x=-1$and check the result.

$\begin{array}{c}3(-1+4)=9\\ 3\left(3\right)=9\\ 9=9\end{array}$

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