Arrange these in increasing order

Can someone me do math because i am having a breakdown rn because i don’t get it

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

Solve each quadratic equation by factoring and using the zero product property. x^2 + 18x = 9x