Algebra Demystified 2nd Ed

250 algebra De mystif ieD

PRACTICE

1. Andy is 3 years older than Bea and Bea is 5 years younger than Rose. If
   Rose is 28, how old are Andy and Bea?


2. Michele is 4 years younger than Steve and three times older than Sean.
   If the sum of their ages is 74, how old are they?


3. Monica earns three times per hour as John. John earns $2 more per hour
   than Alicia. Together they earn $43 per hour. How much is each one’s
   hourly wage?

✔SOLUTIONS

1. Because Rose is 28 and Bea is 5 years younger than Rose, Bea is 28 − 5 =
   23 years old. Andy is 3 years older than Bea, so Andy is 23 + 3 = 26 years old.


2. Let x = Michele’s age. Steve is 4 years older, so his age is x + 4. Sean is
   one-third Michele’s age, so his age is 331 x = x.

xx x

x x

x x

x

+ ++=

++=

++











=

()

()

(

4

3

74

24

3

74

32 4

3

374

32 ))(++) 







=

++=

+=

−−

34 3

3

222

612 222

712 222

12 12

x

xx

x

77 210

210

7

30

x

x

x

=

=

=

Michele is 30 years old; Steve is x + 4 = 34; and Sean is x

2

30

3

== 10.

We can avoid the fraction x 3 in this problem if we let x represent Sean’s

age. Then Michele’s age would be 3x; and Steve’s, 3x + 4.

PRACTICE

1. Andy is 3 years older than Bea and Bea is 5 years younger than Rose. If