In the early 1970s, the NBC television network presented The Bill Cosby Show,in

which the popular comedian played Chet Kincaid, a Los Angeles high school physical

education teacher. In the episode “Let xEqual a Lousy Weekend,” Chet must substitute

for the algebra teacher. He and the entire class are stumped by the following problem:

How many pounds of candy that sells for $0.75 per lb must be mixed with

candy that sells for $1.25 per lb to obtain 9 lb of a mixture that should sell for

$0.96 per lb?

The smartest student in the class eventually helps Chet solve this problem. In

Exercise 31of Section 4.3,we ask you to use a system of linear equations,the topic

of this chapter, to do so.

Systems of Linear Equations

4.3 Applications of Systems of Linear Equations

Equations in Two

Variables

4.2 Systems of Linear

Equations in Three

Variables

4.3 Applications of

Systems of Linear

Equations

4.4 Solving Systems of

Linear Equations by

Matrix Methods

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4

CHAPTER