GOAL 1 DRAWING A DIAGRAM

3.5 Linear Equations and Problem Solving

EXAMPLE 1

Extra Example 1

A page of pictures for a yearbook is inches by 11

inches. The top margin is inch and the bottom margin

is inches. The space between the pictures is inch.

How high can each picture be to fit seven down the length of the page?

18

23

411

4

3

16

Click to see the solution

Checkpoint

Three pictures that are each inches wide are to be

placed on a page that is inches wide. If you leave

equal space between pictures, how much space can you

put between them if the left margin is inch and the right

margin is inches?

52

8111

2

3

451

8

1The space between pictures should be 1 in.

8

GOAL 2 USING TABLES AND GRAPHS AS CHECKS

EXAMPLE 2

3.5 Linear Equations and Problem Solving

Extra Example 2At West High School, 362 students take Spanish. This number has been increasing at a rate of 20 per year. The number of students taking French is 259 and has been decreasing at a rate of about 3 per year. At these rates, when will there be two times as many students taking Spanish as taking French?

Click to see the solution

CheckpointAt North High School, 176 students buy non-spiral notebooks from the school store. This number has been increasing at a rate of about 24 per year. The number of students buying spiral notebooks is 331 and has been decreasing at a rate of about 15 per year. At these rates, when will the number of spiral notebooks sold be half the number of non-spiral notebooks sold?

EXAMPLE 3

It will take 9 years.

Extra Example 3Jim can run 11 ft/sec and Sarah can run 13 ft/sec. How far ahead of Sarah must Jim be not to fall behind Sarah in the first 15 seconds that they run?

Click to see the solution

CheckpointThe winning speed at the Indianapolis 500 auto race in 1990 was about 186 mi/h. The winning speed in 1997 was 146 mi/h. About how many hours longer was the race in 1997 than in 1990?

It was approximately 0.74 hours (44 minutes) longer in 1997 than in 1990.