Math Word Problems Demystified - A Self Teaching Guide

IMPLEMENTATION: Solve the equation:

3

4

ð 20 þxÞ¼ 1 ð 20 
xÞ

41

1



3

41

ð 20 þxÞ¼

4

1

ð 20 
xÞ

3 ð 20 þxÞ¼ 4 ð 20 
xÞ

60 þ 3 x¼ 80 
 4 x

60 þ 3 xþ 4 x¼ 80 
 4 xþ 4 x

60 þ 7 x¼ 80

60 
 60 þ 7 x¼ 80 
 60

7 x¼ 20

71 x

7

¼

20

7

x¼ 2

6

7

miles per hour

EVALUATION: Check to see if the distance going downstream is equal to
the distance going upstream usingD¼RT.

DownstreamD¼

3

4

ð 20 þxÞ

¼

3

4

20 þ 2

6

7



¼

3

4

22

6

7



¼ 17

1

7

miles

UpstreamD¼ 1 ð 20 
xÞ

¼ 120 
 2

6

7



¼ 17

1

7

miles

LESSON 13 Solving Distance Problems 141