Please HELP! Solve for X. I know it is probably easy but I simply don't understand D: PLEASE!

Given f(x) = x − 7 and g(x) = x2 . find g(f( g(f(4))

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

What are the solutions of the equation x4 – 5x2 – 14 = 0? use factoring to solve. someone !