Chapter 0.2, Problem 18E

To determine

To calculate:have to find the age of Brianne and Camila.

Answer to Problem 18E

The age of Brianne and Camila 12 and 4respectively.

Explanation of Solution

Suppose the age of Brianne and Camila is B and C respectively

Given information:

B is three times older than C:

  $B=3\times C\mathrm{...}\left(\text{i}\right)$

And four year now B is two times older than C:

  $B+4=2\left(C+\text{4}\right)=2C+8\mathrm{...}\left(\text{ii}\right)$

Apply the distributive property.

  $\begin{array}{l}\Rightarrow B+4=2C+8\\ \Rightarrow B=2C+8-4\\ \Rightarrow B=2C+4\mathrm{...}\left(\text{iii}\right)\end{array}$

Calculation:

From the equation (i) and (ii), we get

  $\Rightarrow 3C=2C+4$

  $\Rightarrow 3C-2C=4$

  $\Rightarrow C=4$

Place the value of C in equation (i), we get

  $\Rightarrow B=3C=3\times 4=12$

  $\Rightarrow B=12$