Math Word Problems Demystified - A Self Teaching Guide

SOLUTIONS:

1. 7þ 4 x¼ 31


2. 2x
   5 ¼ 15
   3.^12 xþ 8 ¼ 19


3. 2xþ1.20¼1.80


4. xþ 2 x¼ 30

Finally, it is necessary to be able to write an equation for two related

unknowns using one variable.

EXAMPLE:Write an equation for this problem: ‘‘One number is 10 more

than another number and their sum is 16.’’

SOLUTION:Letx¼the smaller number andxþ 10 ¼the larger number.

The equation isxþxþ 10 ¼16.

EXAMPLE:Write an equation for this problem: ‘‘One number is five times

as large as another number. If three times the smaller number is subtracted

from the larger number, the answer is 20.’’

SOLUTION:Letx¼the smaller number and 5x¼the larger number. The

equation is 5x
 3 x¼20.

Try These

Write an equation for each:

1. The smaller number is^12 of the larger number. Find the numbers if
   their sum is 36.


2. A certain number exceeds another number by 6. If their sum is 56, find
   the numbers.


3. One number is 8 more than twice another number. Find the numbers if
   their sum is 50.


4. What number increased by^14 of itself is equal to 5?


5. Two times a number is 6 more than^12 the number. Find the numbers.

86 LESSON 8 Algebraic Representation