Given:
You and your friend each purchase an equal number n of magazines.
Your magazines cost = $1.50 each
Your friend's magazines cost = $2 each
Total cost = $10.50
To find:
The equation to find number of magazines you purchased.
Solution:
Your magazines cost = $1.50 each
Your friend's magazines cost = $2 each
Number of magazines purchased by you and your friend = n
Total cost =

It is given that total cost is $10.50.


Divide both sides by 3.50.


Therefore, required equation is
and the number of magazines purchased by you is 3.