The number of messages Kaitlyn, Tony and Austin sent are 13, 18 and 72 messages respectively.
<h3>How to write and solve equation?</h3>
let
- Number of messages Kaitlyn sent = x
- Number of messages Tony sent = x + 5
- Number of messages Austin sent = 4(x + 5)
- Total messages = 103
103 = x + (x + 5) + 4(x + 5)
103 = x + x + 5 + 4x + 20
103 = 6x + 25
103 - 25 = 6x
78 = 6x
x = 78/6
x = 13
Number of messages each sent:
Number of messages Kaitlyn sent = x
= 13 messages
Number of messages Tony sent = x + 5
= 13 + 5
= 18 messages
Number of messages Austin sent = 4(x + 5)
= 4(13 + 5)
= 4(18)
= 72 messages
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Answer:
After 2 seconds
Step-by-step explanation:
First step is find an equation of velocity:
h(t)=-16t2+64t+112. The velocity function is derivated from position function, so we should do that.
v(t)= h´(t)= -16*2*t+64 ⇒ v(t)= -32t+64.
Now we know the arrow reach the maximun height when this velocity is equal to zero when t>0.
0=-32t+64 ⇒ 32t=64, split each member for 32 ⇒
=
t=2. That means after 2 sec. the arrow reach the maximum height
Answer:
DC = 3
Step-by-step explanation:
Based on triangle similarity theorem, we would have the following equation:

Plug in the values



Cross multiply
3(9 + DC) = 9×4
27 + 3DC = 36
Subtract 27 from each side
3DC = 36 - 27
3DC = 9
Divide both sides by 3
DC = 9/3
DC = 3
Answer:
and 
Step-by-step explanation:
The equation of the isotope decay is:

14-Carbon has a half-life of 5568 years, the time constant of the isotope is:


The decay time is:
(There is no a year 0 in chronology).

Lastly, the relative amount is estimated by direct substitution:





Answer:
Kenjii can use 13.19 kilowatt-hour.
Step-by-step explanation:
Giving the following information:
Kenji's electricity bill costs $21.56 per month plus $2.46 per kilowatt-hour.
<u>First, we will structure the total cost formula:</u>
Total cost= 21.56 + 2.46*x
x= kilowatt-hour
54= 21.56 + 2.46x
32.44= 2.46x
13.19= x
Kenjii can use 13.19 kilowatt-hour.