2. suppose that y varies directly with x and inversely with z, and y = 18 when x = 15 and z = 5. write the equation that models the relationship. then find y when x = 21 and z = 7.

Step 1: y=kx/z

Step 2: k=6

Step 3: x=4

Step-by-step explanation: hope this helps :)

45

step-by-step explanation:

to find a percentage, add a decimal in front and multiply it by the other number.

.25 times 180= 45

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: