Can someone help me with this please???

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.

Simplify the expression 10/11(22z) + (a+5) -1

Im so bad at fractions they are not my best math thing to work on