Ok so I must be stupid but pls help

What is the solution of log2  (3x  -  7)  =  3? 4 5

What is the value of x when x + 7 = 21?

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