1. How many area codes were possible before 1995 2. According to the post-1995 rules how many area codes are possible today?
3. According to these conditions, how many 7-digit numbers are possible in a single area code
4. Using your answers to the previous questions, determine how many 10-digit numbers are possible in North America.

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:

step-by-step explanation:

what does 'mandy have ben 780 bottle caps. ' mean?

srry ask agian

step-by-step explanation:

the answer is b.

64

step-by-step explanation:

c=2πr=2·π·8≈64