How do i do this problem i am stuck on it please help me

5x + 2 = 12 solve the following equation. then place the correct number in the box provided.

Steve wants to develop a way to find the total cost of any item including sales tax. the sales tax in his city is 6%. his friend jenna writes the expression x + 6x where x is the cost of the item. explain whether her expression is correct based on the situation.

Find the area of the region that is inside r=3cos(theta) and outside r=2-cos(theta). sketch the curves.