Please help with these (algebra)

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.

Tom had a total of $220 and he spent $35 on a basketball ticket . what percent of his money did he have left?

An apartment has a replacement cost of $950,000 and contents valued at $1,450,000. it has a classification of a and a territory rating of 3. find the annual premium a) $10,185 b) $9,230 c) $3,155 d) $13,830