The distance traveled in a car varies directly as the amount of gasoline used. if a car travels 520 miles and uses 26 gallons of gas, find the constant of variation or miles per gallon. a) 18 mpg b) 20 mpg c) 22 mpg d) 24 mpg\

guess at question:

a vertical line intersects the graph of g(x,y) = 0 at two points. what conclusion follows about the function f(x) implicitly defined by g(x,f(x)) = 0?

the domain of f(x) cannot include the x coordinate of any such vertical line.

informally, f(x) is not a function, and

g(x,y)=0 cannot be solved for y uniquely.

the relation r = {(x,y) such that g(x,y) = 0} is a function if

for all (a,b) ∊ r and (c,d) ∊ r, a=c implies b=d.

step-by-step explanation: