Can somone plz tell me which one is a function?

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

What is the interquartile range of this data set? 2, 5, 9, 11, 18, 30, 42, 48, 55, 73, 81

Apiling for a high-rise building is pushed by two bulldozers at exactly the same time. one bulldozer exerts a force of 1250 pounds in a westerly direction. the other bulldozer pushes the piling with a force of 2650 pounds in a northerly direction. what is the direction of the resulting force upon the piling, to the nearest degree? a. 65 n of w b. 25 n of w c. 45 n of w d. 35 n of w