Which graph shows a set of ordered pairs that represents a function?
( i can't attach the pictures so i will write the coordinates for each)
a: (-5-,-3)
b: (-5-,-,3)
c: (-4-3)
d: (-4-,-,-1)

(they aren't attached by any lines or anything)

B represents a function.

Step-by-step explanation:

Recall these characteristics of a "function:"

Only one y-value can be associated with each x-value.  

Thus, A could not represent a function because there are two points with x = 1 and two different y-values:  (1, 1) and (1, -2).  

B represents a function because for each input (x-value) there is one and only one y-value associated.

C not a function:  (2, 3) and (2, -3) have two different y-values associated with one x-value (2).

D not a function:  (-3, 4) and (-3, -4) (see A and C, above)

step-by-step explanation:

the original amount doesn't ''re just looking for the time it takes for 1/2 of the substance to we have

(1/2) =)     take the ln   of both sides

ln (1/2)   = )   and we can write

ln(1/2) = ) lne     and lne   = 1     so we have

ln(1/2) = -.1092t     divide both sides by -.1092

t = ln(1/2)/-.1092 = about 6.347 days = about 6.3 days (rounded)

i think the answer is b x = 1, y = 35/2