drawing its graph 

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 42andearns7 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 110plus7 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