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:

Step-by-step explanation:

To get
you needed to divide the numerator and denominator by 3.
Answer:
It's 22.5 inches because the breadth is grater than the length
Answer: −2.4f − 22
Step-by-step explanation: simply combine like terms. -2.7f + .3f would be -2.4f, and -14 - 8 is -22.
steps
(x) = 5x^2-3x+7
refine
x=5x^2-3x+7
Switch sides
5x^2-3x+7-x=x-x
Subtract x from both sides
5x^2-4x+7=0
Solve with the quadratic formula