PLEASE HELP THIS IS A GRADE

Identify which functions are exponential

1- y=(2.7x)squared
2- f(x)= 4 to the x
3- y= 0.5x+1
4- y= 125(2)to the n+8

Twenty points. suppose that one doll house uses the 1 inch scale, meaning that 1 inch on the doll house corresponds to 1/2 foot for life-sized objects. if the doll house is 108 inches wide, what is the width of the full-sized house that it's modeled after? in inches and feet