Arsenic-74 is used to locate brain tumors. It has a half-life of 17.5 days. 90 mg were
used in a procedure. Write an equation that can be used to determine how much of
the isotope is left after x number of half-lives.


How much would be left after 70 days?

Answers

Answer 1

After x half-lifes, the amount of the isotope is:

A(x*T) = 90mg*e{-x*ln(2)}

And after 70 days, there are 5.628 mg

What is the half-life?

We define the half-life as the time such that the inital amount of a given substance reduces to half of it.

If the half-life is T, the amount of the substance can be written as:

A(t) = a*e^{-λ*t}

Where λ = ln(2)/T.

and a is the initial amount.

In this case, T = 17.5 days, then:

λ = ln(2)/17.5 days = 0.0396 / day

And we also have a = 90mg

Then the exponential equation is:

A(t) = 90mg*e^{-t*0.0396 / day}

After x half-lifes, the amount of the isotope left is:

A(x*T) = 90mg*e^{-x*T*ln(2)/T} = 90mg*e^{-x*ln(2)}

And after 70 days the amount is:

A(70 days) = 90mg*e^{-70 days*0.0396 / day} = 5.628 mg

If you want to learn more about exponential decays, you can read:

https://brainly.com/question/11464095

Answer 2

Answer:

Y=90mg(0.5)^5


1.86 after 70 days

Step-by-step explanation:


Related Questions

Which of the following inequalities matches the graph?

Answers

Answer:

x ≤ -7

Step-by-step explanation:

On the graph we can see that:

-the pink solid line is where x= -7 and y can have any value, so is either first or second choice.

-the pink area includes numbers that are equal or less then -7 ( such as -8, -9,-10,...) so the inequality must be x ≤ -7 (the second choice. )

See the line is parallel to y axis

Means x is constanty is varrying

So

x intercept is (-7,0)

X is constant -7

Hence the inequality is

x≤-7

Find M angle B.
Round to the nearest degree.

Answers

Answer: 41

Step-by-step explanation:


The value 3pie/16 is a solution for the equation 2cos^2(4x)-1=0 true or false

Answers

the answer is true i had the same question

Answer:

This is true

Step-by-step explanation:

What is the most common amount of hours students spent studying? (2 points)

A line plot with the title, time students spent studying, and the line is measured in hours. The horizontal line goes from one third to three. In between, there are seven tick marks labeled as two thirds, one, one and one third, one and two thirds, two, two and one third, two and two thirds. The tick mark one third has two xs, the tick mark two thirds has one x, the tick mark one has four xs, the tick mark one and one third has three xs, the tick mark one and two thirds has three xs, the tick mark two has five xs, the tick mark two and one third has three xs, the tick mark two and two thirds has two xs, and the tick mark three has two xs.

a
1 hour

b
one and one third hours

c
2 hours

d
3 hours

Answers

the answer is a 1 hour . I just had that question and got it right !!

20 = (-10) = (-20) +10

1) Is the equation up there true or false?

2) Support your decision below.

Help quick

Answers

Answer:

No, 20 ≠ -10

Step-by-step explanation:

20 = (-10) = (-20)+10

20≠-10=-20+10

20≠-10=-10

What is the rule and how do you find n? 100 points and brainliest to answer!

Answers

Answer:

n = 6

Step-by-step explanation:

Let's convert the x and y values into (x,y) form.

(x, y) ⇒ (3, 5), (4, 7), (n, 11), (8, 15)

Now, let's find the rule in slope intercept form. To find the equation in slope intercept form, pick any two points. Then find the slope of the line.

⇒ (3, 5) and (4, 7)

Now, find the slope using the slope formula.

[tex]\dfrac{y_{2} - y_1}{x_2 - x_1} = \text{Slope}[/tex]

[tex]\rightarrow \dfrac{7 - 5}{4 - 3} = \text{Slope}[/tex]

[tex]\rightarrow \dfrac{2}{1} = 2 =\text{Slope}[/tex]

Now, let's use point slope form to find the equation in slope intercept form.

[tex]y - 5 = 2(x - 3)[/tex]

[tex]\rightarrow y - 5 = 2x - 6[/tex]

[tex]\rightarrow y = 2x - 1 \ \ \ \ \ (\text{Rule})[/tex]

Now, substitute the value of y into the equation.

[tex]11 = 2x - 1[/tex]

[tex]\rightarrow 12 = 2x[/tex]

[tex]\rightarrow \boxed{x = n = 6}[/tex]

Take two points find equation

(3,5)(4,7)

Slope:-

m=7-5/4-3=2

Equation in point slope form

y-5=2(x-3)y=2x-6+5y=2x-1

Now put n

11=2n-12n=12n=6

help please? with a working out would be nice

Answers

Answer:

280 cups total.  

Step-by-step explanation:

Tricky.  The explanation and answers are on attached images.

I just need 13⅗% as a decimal please thanks

Answers

the answer to 13 3/5% as a decimal

0.136

 

please no guessing (WILL GIVE BRAINILIST)

STATISTICS

Answers

Answer:

#2 mean is 90.3846154 and range is 40

#3 mean 91.9230769 and range is 20

(you might have mixed the second and third graph up)

Step-by-step explanation:

The Hire Purchase priceola microwave
a deposit of $600 and equal monthly
installmentsof$4s. Howmany installmen,

Answers

Answer:

150

Step-by-step explanation:

$600/$4 =150

=150 installments

I am so confused. Help.

Answers

[tex]\large\sf\underline{ANSWER:}[/tex]

√3

x is the length of the third side

x²+1² = 2² { Pythagorean Theorem}

x²+1 = 4 {Simplify}

x²=3 {Subtract 1 from each side}

x=√3 {Take the square root of each side}

The Length of the third side is √3

#[tex]\large\sf\underline{CarryOnLearning}[/tex]

You decide to put $2,000 in a savings account to save for a $3,000 down payment on a new car. If the account has an interest rate of 4% per year and is compounded monthly,
how long does it take until you have $3.000 without depositing any additional funds?

Answers

Answer:

12.5 years = 216 months

Step-by-step explanation:

4% of 2000= $80

1000/80=12.5

It will take 12.5 years to make $1000 on its own without adding additonal funds.

Lisa is checking out at the bookstore. Each book (b) costs $1.50 and she has a $5 off coupon she can use. She wants to spend $25 or less in the bookstore. How many books can Lisa buy?

Answers

Answer:

20

Step-by-step explanation:

Given:

Lisa is checking out at the bookstore.

Each book (b) costs $1.50 and she has a $5 off coupon she can use.

She wants to spend $25 or less in the bookstore.

Solve:

Since there is a $5 off coupon..

$1.5b - $5.00<=$25.00

$1.5b<= $30.00

$1.5b/1.5 = $30.00/1.5

b=20

Lisa can buy 20 book.

~lenvy~

The ratio of red candy to green candy in a bag is 3 to 4
If there were 36 pieces of green candy in the bag, how many pieces of candy in the bag were red?

Answers

Answer:

27

Step-by-step explanation:

we know that 4 multiplied with something is 36

=>     4x = 36

=>     x = 36/4

=>     x = 9

so we have to multiply 3 with 9

=>     3*9 = 27

factor 1/2 out of 1/2x + 9/2

Answers

Answer:

Equation would be x + 9/2.

Step-by-step explanation:

Factoring out means taking out a Number, or an unknown quantity.

So, Factor out 1/2:

New equation with old step by step:

Step 1:

Remove 1/2 from 1/2x + 9/2

Step 2:

Equation should be: x + 9/2.

New equation:

x + 9/2

Joe drove 567 miles in 9 hours.
At the same rate, how many miles would he drive in 5 hours

Answers

Answer:

answer down below

Step-by-step explanation:

it would be 315

Answer:

13 hours

Step-by-step explanation:

567/9=63

she drives 63mph

it will take her 13 hours to drive

Two numbers have a sum of 1,212 and a difference of 518. What are the two numbers?

Answers

Answer:

347 and 865

Step-by-step explanation:

Let the two number be x and y

Therefore, from the given information:

x + y = 1212

x - y = 518

Rewrite both equations to make x the subject:

x = 1212 - y

x = 518 + y

Equate equations and solve for y:

1212 - y = 518 + y

     694 = 2y

         y = 347

Substitute found value of y into one of the equations and solve for x:

x = 518 + 347

x = 865

Therefore, the two numbers are 347 and 865

helllllppp!!!!!!!!!!!!11 marking brainliest!

Answers

Hello!

Let the unknown number be x.

Subtract 5:

x-5

Double the result: (multiply the result times 2):

2(x-5)

Hope everything is clear.

Let me know if you have any questions!

#KeepLearning

:-)

HELP PLEASE. Check picture. I have tried but cannot seem to get it.

Answers

Answer:

[tex]884^{-7}[/tex]

Step-by-step explanation:

Start by simplifying the denominator of the fraction. When multiplying exponents of the same base, you can add the exponents. This is also known as the product rule.

[tex]a^x\cdot a^y=a^{x+y}[/tex]

["a" is the base, and "x" and "y" are the exponents]

Using this we find...

[tex]884^{58}\cdot884^{46}=884^{58+46}=884^{104}[/tex]

When dividing exponents of the same base, you can subtract the exponents. This is also knows as the quotient rule.

[tex]a^x\div a^y=a^{x-y}[/tex]

Using this we find...

[tex]\frac{884^{97}}{884^{104}}=884^{97-104}=884^{-7}[/tex]

Answer:

[tex]884^{-7[/tex]

Step-by-step explanation:

≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡

Before we begin solving, let's review a few rules of exponents.

If an exponent is multiplying with another exponent and their bases are the same, you can simply add the exponents.If an exponent is dividing with another exponent and their bases are the same, you can simply subtract the exponents.

≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡

⇒ [tex]\dfrac{884^{97} }{884^{58} \times 884^{46} }[/tex]

⇒ [tex]\dfrac{884^{97} }{884^{58 + 46}}[/tex]                                                                                       [#1]

⇒ [tex]\dfrac{884^{97} }{884^{104}}[/tex]

⇒ [tex]884^{97 - 104[/tex]                                                                                     [#2]

⇒ [tex]\boxed{884^{-7}}[/tex]

≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡

Farm workers plant 980 beans in 35 rows. How many beans do they plant in one row

Answers

980/35 = 28 beans per row

André paid a $65 annual fee to register with a car rental company. The company charges $8.50 for each hour a car is rented. What is the rate of change of the function that represents André's cost for renting a car over the course of a year?
A. $8.50 per hour
B. $65 per year
C. $73.50 per hour
D. $73.50 per year

Answers

Answer:

I dont know if this is the right answer, but my best guess is that it is A.

Step-by-step explanation:

The rate of change of the function that represents André's cost for renting a car over the course of a year $8.50 per hour.

What is the rate of change?

The rate of change is the cost by which the cost of renting the car increases by. The cost of renting the car increases by $8.50 per hour.

The annual fee can be described as the fixed cost of renting the car per year.

To learn more about fixed cost, please check: https://brainly.com/question/25879561

Given the function g(x)=√x+4, which of the following values cannot be the domain of g?
A. X=1
B. X=2
C. X=12
D. X=-5

Answers

Answer:

  D.  x = -5

Step-by-step explanation:

The square root function is only defined for non-negative arguments. For the function ...

  [tex]g(x)=\sqrt{x+4}[/tex]

this means we must have ...

  x +4 ≥ 0

  x ≥ -4 . . . . . . subtract 4 from both sides

All of the numbers on your answer choice list are more than -4 except -5.

  x = -5 is not in the domain of g(x)

Answer the questions in the image.

Answers

#1

Radius=9/2=4.5in

Area:-

πr²4.5^2π20.25πin^263.58in^2

#2

Side=a=4in

Area:-

a²4²16in^2

#3

Area of the white part=Area of circle-Area of square

63.585-1647.585in^2

#4

Probability

16/63.5850.252

#5

Probability

47.58/63.5850.75

Answer:

1. 63.62 in².

2. 16 in².

3. 47.62 in².

4. 0.25 .

5. 0.74 .

Step-by-step explanation:

1.

Solution,

Given,

Diameter = 9 inch.

Now,

Area = πr²

Diameter = r²

Then,

Area = 1/4 πd²

= 1/4 π9²

= 63.62 in².

2.

Solution,

Given,

Length of a Side = 4 inch.

Now,

Area = L²

= 4²

= 16 in².

3.

Solution,

Given,

Area of the Circle = 63.62 in².

Area of the Square = 16 in².

Now,

Area of The White Part of the Circle = Area of Circle - Area of Square

= 63.62 in² - 16 in².

= 47.62 in².

4.

Solution,

Given,

Area of the Square = 16 in².

Area of the Circle = 63.62 in².

Now,

The probability of landing in the Square = Square Area / Circle Area

= 16 / 63.62

= 0.25 .

5.

Solution,

Given,

White Part of the Circle = 47.62 in².

Area of the Circle = 63.62 in².

Now,

The probability of landing in the white Part = White Area / Circle Area.

= 47.62 / 63.62

= 0.74 .

Find the value of x.
A. 53°
B. 72°
C. 39°
D. 48°

Answers

Answer: 53

Step-by-step explanation:

The circumference of a circle is 43.96 yards. What is the circle's radius?

Answers

Answer:

Step-by-step explanation:

Radius = circumference / 2π

= 43.96 / 2π

= 7.00 yards to the nearest hundredth.


Solve each inequality.
X+5 < 6
Pls help

Answers

Answer:

x<1

Step-by-step explanation:

You would just subtract 5 from both sides of the equation. The sign does not flip because you are not multiplying or dividing any negative number across the sign.  So simply x+5 (-5) < 6 (-5). On the left side the 5 would cancel out.  on the other side 6-5 is equal to 1.

Answer:  x<1

Answer: x < 1

Step-by-step explanation: x + 5 < 6

Subtract 5 from both sides,

x < 1

You are ordering sweatshirts for your baseball team. The bar graph shows how many of each size you will need. Which choice below is NOT true?

Answers

Answer:

- more people need extra large sweatshirts than large sweatshirts

Answer: C

Step-by-step explanation:

More people need extra large sweatshirts than large sweatshirts.

Find x 20 and 15 geometric mean

Answers

Answer: 17.320508075689

Step-by-step explanation:

Please guys help me , i need help with this math work im not doing so good un math

Answers

Answer: If you need help on both here are both answers.... Answer 1- f(x)=6.50x+48.00 because Let

x ----> the number of adult tickets

f(x) ----> amount of money collected

To find the amount collected multiply the number of adult tickets by the cost and multiply the number of student tickets  by the cost, and then sum the two quantities

The linear equation that represents this problem is

f(x)=6.50x+4.00(12)

f(x)=6.50x+48.00

and for Answer 2- Is 4

Karen has just baked 17 cookies. She wants to put them in paper bags in groups of 6. How many groups of 6can she make ? How many cookies will she have remaining ?

Answers

Answer:

She can make 2 groups of six, with five cookies remaining

Step-by-step explanation:

First, divide 17 by 6 to get 2 5/6. The whole number is the number of groups she can make, and the fraction is how many are left over. She can make two groups, with five left over.

Hopefully this helps - let me know if you have any questions!

Answer:

2 groups with 5 left over.

Step-by-step explanation:

to solve, take 17 and divide it by 2. since we only have 17 cookies, we round down no matter what. to get the left over, multiply 2 by 6, then subtract by 17.

please mark as brainlest.

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