8 less than the product of a number and 4 is 20

What is the simplified expression for 6(2(y+x))

Pls! does anybody know a shortcut for answering these types of questions in the future?

Organic apples are on special for $1.50 per pound. does total cost vary inversely or directly with the number of pounds purchased? find the cost of 3.4 pounds of apples. a. inversely: $5.10 b. directly; $5.10 c. inversely: $2.27 d. directly; $2.27