Max has 3 textbooks and 2 notebooks in his backpack. The total
weight of his backpack and its
content is 10,5 pounds. Each
textbook weighs 2.5 pounds. Each
notebook weighs 0.25 pound. What
is the weight of Max's empty
backpack?

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: