Chapter 3.1, Problem 91SR

To determine

To solve the given equation and check the solution.

Answer to Problem 91SR

  $a=3.2$

Explanation of Solution

Given information: $7a-3a+2a-a=16$ .

Calculations: We have given and equation $7a-3a+2a-a=16$ . We need to solve it for variable a.

In order to solve it for a, we need to get a alone on left side.

First we need to combine like terms on left side

Combine like terms $7a-3a+2a-a$ , we get

  $5a=16$

Divide both sides by 5, we get

  $\begin{array}{l}\frac{5a}{5}=\frac{16}{5}\\ \Rightarrow a=\frac{16}{5}=3.2\end{array}$

Therefore, solution of the given equation is $a=3.2$ .

Now, let us check the solution.

Substitute $a=3.2$ in $7a-3a+2a-a=16$ , we get

  $7(3.2)-3(3.2)+2(3.2)-(3.2)=16$

On simplifying left side, we get

  $\begin{array}{l}22.4-9.6+6.4-3.2=16\\ \Rightarrow 16=16\end{array}$ .

We got left side = right side.

Hence our solution $a=3.2$ is absolutely correct.