Answer: $19.6
Step-by-step explanation:
Linear function: f(x)=mx+c
, where m= rate of change in f(x) with respect to x.
c = Initial value.
Let c = Initial value of card , m= Charge per minute
x= Number of minutes calling time.
Then, 25.06= 38m+c (i)
21.03=69m+c (ii)
Eliminate (ii) from (i)

Put m in (i) , we get

i.e. f(x)=-0.13x+30
if x=80 then
f(80)= -0.13(80)+30
=-10.4+30
=19.6
Hence, the remaining credit after 80 minutes of calls = $19.6
1yd=3ft...so 39ft=(39/3)=13yds
1mins =60seconds
13/60=0.22yds/secs
Answer:
How many people are not allergic to any of the three choices? 22
How many people are allergic to all three choices? 1
How many people are allergic to both dogs and cats but not allergic to pollen? 7
How many people are allergic to cats only? 18
Collinear means the points are lying on single straight line
So B)with K G R form a single straight line is correct
Coplanar means the points are in the same plane
So D)with H G K N on the same plane is correct
Overall,B) and D) are correct