Home > MC2 > Chapter 7 > Lesson 7.1.2 > Problem7-19

7-19.

Write an equation to represent the situation below and answer the question. You may use the 5-D Process to help you.

Andrew just opened a new office supply store. He has been keeping track of how many customers visit his store. During his second week, he had $18$ more customers than he did the first week. The third week, he had four less than twice as many customers as he had during the second week. In his fourth week of business he had $92$ customers. If he had $382$ customers in total during his first four weeks of business, how many customers did he have during the second week?

Create an expression to represent this problem using a variable, $x$. Try to write and solve for an equation, or if necessary, use the 5-D Process you learned earlier.

Each of the weeks ultimately relates to the first week, so we can define the first week's customers as $x$. Write expressions for each of the other weeks based on the variable.

First week : $x$
Second week: $x + 18$
Third Week: $2(x + 18) − 4$
Fourth Week: $92$

Create an expression by summing up each of the week's customers to total 382 as given by the problem, then solve for the variable. Remember, the second week's customers was 18 more than the first week's ($x$).

$78$ customers