Seven pens and two pencils costs $6.59. seven pens and five cost $7.55. find the cost of one pencil and the cost of one pen.

Let one pen be  and one pencil as , we can produce two equations in terms of  and 

------> Equation 1
------> Equation 2

We can use either Elimination or Substitution method. Let's try the substitution method

Rearranging equation one to get  and substitute into equation 2, gives






We can use either equation one or equation to work out 





The price of one pen is $0.85
The price of one pencil is $0.32