This is preclac, I don’t understand can you please show your steps and explain clearly thank you so much,

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.

Which of the following expressions is equal to 2x^2+8

15 there is a line that includes the point 0,10 and has a slope of 7/4. what is it’s equation in slope intercept form