Chapter 8.5, Problem 40CCR

To determine

An equation and solve it

Answer to Problem 40CCR

The equation is $x+x+36=70$

The solution of the equation is $x=17$

Explanation of Solution

Given:

An atom of chlorine has 36 fewer protons than an atom of iodine. Together, an atom of chlorine and an atom of iodine have a 70 protein.

Rules of Addition/ Subtraction:

• Two numbers with similar sign always get added and the resulting number will carry the similar sign.
• Two numbers with opposite signs always get subtracted and the resulting number will carry the sign of larger number.

Rules of Multiplication/ Division:

• The product/quotient of two similar sign numbers is always positive.
• The product/quotient of two numbers with opposite signs is always negative.

In order to find an equation

Let x be an atom of iodine

Since an atom of chlorine has 36 fewer protons than an atom of iodine as shown below,

  $x+36$

Together they have a total of 70 protons

Thus, the equation is $x+x+36=70$

In order to solve the equation $x+x+36=70$ first add the like terms and then subtract both sides by $36$ and then divide both sides by $2$ and then simplify as below

  $\begin{array}{c}x+x+36=70\\ 2x+36=70\\ 2x+36-36=70-36\\ 2x=34\\ \frac{2x}{2}=\frac{34}{2}\\ x=17\end{array}$

Thus, the solution of the equation is $x=17$