Answer:
Solve what?
Step-by-step explanation:
You didn't put the question.
Answer:
Amount each friend pays for the gift = $20
Step-by-step explanation:
Market price of a gift = $70
The store manager takes $10 off the market price.
Marked down amount = $10
New cost price = Marked price - Marked down amount 
The cost of the gift is divided among three friends.
This means that the cost of gift which is $60 is divided by three to get each one's contribution in the gift.
∴ Amount each friend pays for the gift 
2k - 4 = 2 + k
(Subtract both sides by k)
k - 4 = 2
(Add both sides by 4)
k = 6