How do you know if a relation is a function?

Will give let f(x)=2x and g(x)=[tex]2^{x}[/tex] graph the functions on the same coordinate plane. what are the solutions to the equation f(x)=g(x) ? enter your answers in the boxes x=[? ] or x=[? ]

When a 757 passenger jet begins its descent to the ronald reagan national airport in washington, d.c., it is 3900 feet from the ground. its angle of descent is 6 degrees. how far must the plane fly to reach the run way? a. 37,106 ft b. 37,310.4 ft c. 23,456.6 ft d 2,492.7 ft

42. if 20 men can eat 200 kg of wheat in 40 days, then 10 men can eat 300 kg of wheat in how many days? a) 120 days b) 60 days c) 80 days d) none of these