Question

My chemistry book is 8 years older than my Algebra book. In 6 years the chemistry book will be twice as old as the Algebra book. Show me the variable expressions for the 'now' ages of these books.

Answer 1

x + 14 = 2(x + 6)

x = 2

Explanation:

Let

Algebra book age = x

Chemistry book age = x + 8

In 6 years time

Chemistry book age = x + 8 + 6

= x + 14

Algebra book age = x + 6

the chemistry book will be twice as old as the Algebra book.

x + 14 = 2(x+6)

x + 14 = 2x + 12

x - 2x = 12 - 14

- x = - 2

Divide both sides by -1

x = 2

Check:

Chemistry book age = x + 14

= 2 + 14

= 16

Algebra book age = x + 6

= 2 + 6

= 8