Chapter 1.3, Problem 42HP

To determine

Write a real − world problem that uses the expression with two variables.

Answer to Problem 42HP

Kate needs to read  $\frac{x+y}{72}$ pages each day

Explanation of Solution

Given:

Write an algebraic expression that has two different variables and two different operations: addition, subtraction, multiplication or division. Then write a real − world problem that uses the expression.

Write a real − world problem that uses the expression with two variables.

Concept Used:

To set up or model a linear equation to fit a real-world application, we must first determine the known quantities and define the unknown quantity as a variable. Then, we begin to interpret the words as mathematical expressions using mathematical symbols.

When dealing with real-world applications, there are certain expressions that we can translate directly into math.

Calculation:

Kate has to read two books over her 72 − day summer vacation. Her plan is to read the same number of pages each day.

First, Kate should decide on her variables. She doesn't know the number of pages in either book, so she will need two variables.

Let  $x$  equal the number of pages in the first book.

Let  $y$  equal the number of pages in the second book.

Next, write a variable expression using  $x$  and $y$ .

In total Kate will have to read  $x+y$  pages. She is going to read the same number of pages each of the 72 days of vacation.

This means she should divide the total number of pages by 72 to find out how many pages she needs to read each day.

Her expression is $\frac{x+y}{72}$

The answer is Kate needs to read  $\frac{x+y}{72}$ pages each day if  $x$  is the number of pages in the first book and  $y$  is the number of pages in the second book.

Thus, Kate needs to read  $\frac{x+y}{72}$ pages each day