Writing an equation and drawing its graph to model a real-world situation: Basic

Introduction

In this lesson, we solve real world problems which are modeled by an equation. The equation describing the problem is written and its graph is plotted.

Example 1

Jenny has savings of $42 and earns $7 for each hour of lawn mowing. If y is the total amount with Jenny and x is the number of hours he works, write and equation in y and x and graph it.

Solution

Step 1:

The equation representing the problem in x and y is

y = 42 + 7x

Step 2:

The plot is

Example 2

Phil's party costs $110 plus $7 for every guest he invites. Let y be the total cost of party and x be the number of guests. Write an equation in x and y and graph it.

Solution

Step 1:

The equation representing the problem in x and y is y =110 + 7x

Step 2:

The plot is