I have no clue what it is so please help me

What term makes it inconsistent y=2x - 4 ?

Aman is 6 feet 3 inches tall. the top of his shadow touches a fire hydrant that is 13 feet 6 inches away. what is the angle of elevation from the base of the fire hydrant to the top of the man's head?

Consider the function f(x)=-5x+3 what is f(-2)