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
Where are the following options?
Answer:
48
Step-by-step explanation:
48=2×2×2×2×3
78=13×2×3
48 has 5 factors.
(5x³ + 4x²) - (6x² - 2x - 9)
-1(6x²) -1(-2x) -1(-9) = -6x² + 2x + 9
5x³ + 4x² - 6x² + 2x + 9
5x³ - 2x² + 2x + 9 Choice D.