Answer: scroll down to find out :)
Step-by-step explanation:
Let's say pens are p and pencils are e.
9p + 5e = 3.20
7p + 8e = 2.90
2p - 3e = 0.30
p = (0.3 + 3e)/2
7(0.3 + 3e/2) + 8e = 2.90
(2.1 + 21e)/2 + 8e = 2.9
e = 0.1, p = 0.3
So, pencils are 10 cents and pens are 30.