What is the value of the expression (81 1/4)^4

What is the value of x in the diagram below?

F(x)=x/2-2 and g(x)=2x^2+x-3 find (f+g)(x)

The boiling point of water at an elevation of 0 feet is 212 degrees fahrenheit (°f). for every 1,000 feet of increase in elevation, the boiling point of water decreases by about 2°f. which of the following represents this relationship if b is the boiling point of water at an elevation of e thousand feet? a) e = 2b - 212 b) b = 2e - 212 c) e = -2b + 212 d) b = -2e + 212