Chapter 8, Problem 18CR

To determine

Translate into an equation and solve

Answer to Problem 18CR

The equation is $x+12=36$

She spent on books is $x=24$

Explanation of Solution

Given:

Noelie spent $36 on books and pens. She spent $12 more on books than she did on pens

Concept Used:

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 translate the sentence into an equation

Let x be the number she spend on books since Noelie spent $36 on books and pens. She spent $12 more on books than she did on pens as shown below,

  $x+12=36$

Thus, the equation is $x+12=36$

In order to solve the equation $x+12=36$ first subtract both sides by $12$ and then simplify further as below:

  $\begin{array}{c}x+12=36\\ x+12-12=36-12\\ x=24\end{array}$

Thus, she spent on books is $x=24$