If x varies jointly as y and z, and x=8 when y=4 and a=9,find z when x=16 and y=6

answer: 193

explanation:

200-7 = 193

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:

we need to see the graph to know but

strong positive is if it is going up from left to right in a straight diagonal line (like this /)

strong negative is the same but from right to left (like this \)

weak negative is the same as strong negative but its more straight line still right to left

and weak positive is the same as strong positive but more a straight line still left to right though.