Answer:
Given that,
The number of grams A of a certain radioactive substance present at time, in years
from the present, t is given by the formula

a) To find the initial amount of this substance
At t=0, we get


We know that e^0=1 ( anything to the power zero is 1)
we get,

The initial amount of the substance is 45 grams
b)To find thehalf-life of this substance
To find t when the substance becames half the amount.
A=45/2
Substitute this we get,


Taking natural logarithm on both sides we get,







Half-life of this substance is 154.02
c) To find the amount of substance will be present around in 2500 years
Put t=2500
we get,




The amount of substance will be present around in 2500 years is 0.000585 grams
Answer:
B. 550
Step-by-step explanation:
550 is the smallest number that becomes 600 when rounded to the nearest hundred
Answer:
For number 5 . a= 3 and b = -1
0.47460844803037 this is the answer
Answer:
Ben received: £140
Step-by-step explanation:
Total amount = £240
Given ratio: 5:7
It means £240 is divided into 12 parts
So 1 part will be equal to: £240/12
1 part = £20
Now given ratio is:
5:7
Multiplying each share with £20
5*(£20) : 7* (£20)
£100: £140
So according to ratio amounts:
Alex received: £100
Ben received: £140
I hope it will help you!