Answer:
It will take about 109.3 seconds for nine grams of the element to decay to 0.72 grams.
Step-by-step explanation:
We can write a half-life function to model our function.
A half-life function has the form:

Where <em>A₀</em> is the initial amount, <em>t</em> is the time that has passes (in this case seconds), <em>d</em> is the half-life, and <em>A</em> is the amount after <em>t</em> seconds.
Since the half-life of the element is 30 seconds, <em>d</em> = 30. Our initial sample has nine grams, so <em>A₀</em> is 9. Substitute:

We want to find the time it will take for the element to decay to 0.72 grams. So, we can let <em>A</em> = 0.72 and solve for <em>t: </em>
<em />
<em />
Divide both sides by 9:

We can take the natural log of both sides:

By logarithm properties:

Solve for <em>t: </em>
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<em />
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So, it will take about 109.3 seconds for nine grams of the element to decay to 0.72 grams.
Step-by-step explanation:
sally needs 7 more Apples, but if Sally is doubling the recipe she will need 14 more Apples
This seems to be an incomplete question. I think you want to know the amount of sugar at which both company will charge the same. Based on this idea, i am answering the question.
Let us assume the quantity of sugar = x
Then
For company A, charge = 7500 + 125.25x
For company B, charge = 5995 + 200.50x
Now
7500 + 125.25x = 5995 + 200.50x
7500 - 5995 = 200.50x - 125.25x
1505 = 75.25x
x = 20
From the above deduction it can be concluded that the quantity of sugar at which the prices of both the companies will be the same is 20 ton.
The required inverse function
= (2x - 3 ) / 4.
Given that,
f(x) = (2x+3) / 2
To find 
<h3>What are functions?</h3>
Functions are the relationship between sets of values. e g y=f(x), for every value of x there is its exists in a set of y. x is the independent variable while Y is the dependent variable.
Let f(x) = y
y = (2x + 3) / 2
y * 2 = 2x + 3
2y - 3 = 2x
x = (2y - 3) / 2
Now replace y = x and x = 
= (2x - 3 ) / 4
Thus, the required inverse function
= (2x - 3 ) / 4.
Learn more about function here:
brainly.com/question/21145944
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Step-by-step explanation:
D.the set of all possible output values.