Note: Full question is attached in image below.
Solution of Problem 3:
Assume that the price before Friday is $p.
On Friday, it goes up by $0.05. So, we get
$(p + 0.05)
On Saturday, it goes down by $0.03. So, we get
$(p + 0.05 - 0.03)
Solution to Problem 4:
In this problem, we just have to substitute the value of p which is given as $2.59. So, we get:
= $(2.59 + 0.05 - 0.03)