Jennifer is 4 years older than harvey. harvey is twice as old as gwen. if gwen is g years old, which expression represents jennifer’s age?

a
2g−4

b
2g

c
2g+4

d
g+4

Can someone answer it, and plot it, for 20 points and brainliest answer? p.s. they're the same ! : )

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.

Icould really use some with this question.