Question

A student bought a book for $7 and a pen. The total cost was $9. Which of the following equations can be used to find the cost of the pen?

Answer 1

7+x=9

Explanation:

if you subtract 7 from both sides of this you will get x=2 so the pen is $2

Answer 2

Total cost = $9

Cost of book = $7

Let the cost of pen be = x

Thus,

x+$7=$9

x=$9-$7

x=$2