Answer:
359.19 And good morning to you
Step-by-step explanation:
Answer:
Initial amount is 523 grams
Amount after 100 years is 52 grams
Step-by-step explanation:
General exponential function for radioactive substances is given by
A(t) = Ao(1/2)^t/t1/2
Where,
A(t) is the amount remaining after t years
Ao is the initial amount of the radioactive substance
t is the number of years required for the radioactive substance to decay to A
t1/2 is the half-life of the radioactive substance
Comparing A(t) = 523(1/2)^t/30 with the general exponential function
Initial amount (Ao) = 523 grams
A(t) = 523(1/2)^t/30
t = 100
A(100) = 523(1/2)^100/30 = 523×0.5^3.333 = 523×0.0992 = 51.8816 = 52 grams (to the nearest gram)
Answer:
6554
Step-by-step explanation:
The sequence 2, -8, 32, -128 has a first term (a1) of 2 and a common ratio (r) of -8/2 = -4. The sum of n terms is given by ...
Sn = a1·(r^n -1)/(r -1)
For your sequence, the sum of 7 terms is ...
S7 = 2·((-4)^7 -1)/(-4-1) = 2(-16384/-5) = 6554
The sum of changes after the 7th day is 6554.
4 because you multiplied the 5 by 2 to get to the 10, so you have to do that to the 2. 2x2=4