Abarrel of water is full. it decreases by 85%. now it has 120 liters of water. how much liters of water did it have to begin with?

800 liters

Step-by-step explanation:

A simple cross multipilcation

It says it has gone down 85%, so only 15% is left.

120 liters is 15% of the original sum.

120 liters      15%

x=                 100%

120*100/15 = 800 liters

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: