.do anybody know how to do these?

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.

For what value of (y) is 3^3/3^y =1/9

Aline that intersects one of two parallel lines intersects the other also always sometimes never