Please help me with this really please

Since the isotope is initially 154 mg, the amount of radioactive isotope left after 64 hours is 9.625 mg

To answer the question, we need to know what radioactive decay is.

Radioactive decay is the spontaneous disintegration of a larger atom to a smaller one

Half-life of a radioactive isotope is the time it takes for the isotope to decay to half its initial value.

The amount left after n half lives is N = (1/2)ⁿN₀ where N₀ = initial mass of isotope.

Given that the half-life of the isotope is 16 hours, and we desire the amount present after 64 hours.

The number of half-lives after 64 hours is n = time/half-life

= 64 h/16 h

= 4

Since we have 154 mg of isotope present, N₀ = 154 mg

Given that

Substituting the values of the variables into N, we have

N = (1/2)ⁿN₀

N = (1/2)⁴ × 154 mg

N = 154 mg/16

N = 9.625 mg

So, the amount of radioactive isotope left after 64 hours is 9.625 mg

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Answer:

Executive summary describes the 'big picture behind your business, what your business has to offer the consumer, and why

Step-by-step explanation:

B is right

By looking at this problem:

  ⇒ must use trigonometric functions:

     ⇒ (look at image attached for further reference)

Let's solve:

          [tex]sin(10)=\frac{a}{13}\\ a = 13sin(10)\\a=2.25743[/tex]

          [tex]cos(10)=\frac{b}{13} \\b = 13cos(10)\\b = 12.80250[/tex]

Make sure to round your answer to four decimal points

Answer:

Hope that helps!

Answer:

23:25

Step-by-step explanation:

Answer:

23/25 23 to 25   23:25

Step-by-step explanation:

Two boys  23 girls=25 children

girls=23

23/25

Answer: Minimum: 0

Quartile Q1: 22.5

Median: 50

Quartile Q3: 77.5

Maximum: 100

Step-by-step explanation:

Answer:

28% as a fraction can be written in many ways.  The most simplest way to convert a percentage to a fraction would just to put it over 100.  For example, 50% would be 50/100 therefore 28% would be 28/100.

However, we can simplify that fraction even more by doing (28/4)/(100/4) which would give us 7/25.

Hope this helps!

To calculate temperature (C ∘ F) Celsius to Fahrenheit for the month, use the following expression.

Temperature is the way to express the hotness or coldness of a body or object surface. The scales of measuring temperature are:

To convert Fahrenheit to Celsius, we use the following formula.

[tex]^oF=^oC\times\dfrac{9}{5}+32[/tex]

The formula to convert Celsius to Fahrenheit is

[tex]^oC=\dfrac{5}{9}(^oF-32)[/tex]

Now, there is no data given in the problem. Thus, the above formula for any data can be used to convert the unit of temperature measurement.

Hence, to calculate temperature (C ∘ F) Celsius to Fahrenheit for the month, use the following expression.

[tex]^oC=\dfrac{5}{9}(^oF-32)[/tex]

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Answer:

GJ = 15

Step-by-step explanation:

GE = 30

GE is the diagonal.

In a parallelogram, the diagonal bisect each other

GJ = GE ÷ 2

     = 30 ÷ 2

GJ = 15

Answer:

1230.9

step by step explanation:

Step-by-step explanation:

how is that math ?

anyway,

*♡ = O

●* = H

arrow up and filed triangle = E

arrow down and 3/4 circle = R

Answer:

67.5 ft^3

Step-by-step explanation:

7.5 * 2 * 3.5   +  3 * 2.5 *2   =  67.5 ft^3

Answer:

n ≤ 4

Step-by-step explanation:

"The difference between a number and seven is less than or equal to -3" can be written as n-7 ≤ -3

n-7 ≤ -3

Add 7 to both sides

n ≤ 4

Answer is n ≤ 4

See picture attached for the math

Answer:

  H  x/10 = 18/8

Step-by-step explanation:

The fact that DE is parallel to CB means DE divides AC in the same proportion that it divides AB. This fact can be used to write a proportion to find x.

__

  [tex]\dfrac{\overline{DC}}{\overline{AD}}=\dfrac{\overline{EB}}{\overline{AE}}\\\\\boxed{\dfrac{x}{10}=\dfrac{18}{8}}\qquad\text{matches choice }\textbf{H}[/tex]

_____

Additional comment

The values used in the other answer ratios are not "corresponding."

Answer:

H

Step-by-step explanation:

∠ADE is a scaled version of ∠ ABC.

So,

18:8

and

10:x

Ratios can be expressed as fractions:

[tex]\frac{8}{18}[/tex] and [tex]\frac{x}{10}[/tex].

Since the scale factor is the same,8/18 has to be the same as 10/x.

Therefore,[tex]\frac{8}{18}[/tex]=[tex]\frac{x}{10}[/tex].

Hope this helps!!!

Please mark me as brainliest!!!

This took a lot of effort.

Answer: 9.3  

I calculated the area of the square, then I calculated the area of the circle.  Then I subtracted the two.

Answer:

5.3

Step-by-step explanation:

A square has equal sides

LXW=A

5x5= 25

diameter of the circle is 5 ft

D/2=R 5/2= 2.5

Area of a circle is [tex]\pi r^2[/tex]  (Pi=3.14)

[tex]3.14 X (2.5)^2[/tex]= 3.14 x 6.25=  19.625.

Area of yellow region

Area of square - Area of circle.

25-19.625 = 5.375 rounded to nearest 10th is 5.3

Answer:

$

15.00

Step-by-step explanation:

Round the costs of the gloves and hat. $9.95 is very nearly $10. And even though $5.25 is over $5 , it is still very close. $10+$5 is $15. This is the estimate.

Answer:

1,280

Step-by-step explanation:

Answer:

1) B. (6,-3)

2) D. (-8,-2)

so clearly...the 2nd one is the least

hope it helps...!!!

Answer:

7.84 / 5.6 is least

Step-by-step explanation:

1.       1.26 / 0.3

= 4.2

2.      7.84 / 5.6

= 1.4

answer of 1.  is 4.2 and 2. is 1.4

1.4 is less than 4.2

Answer:

A, D, E

Step-by-step explanation:

AREA OF SQUARE

[tex](x - 1)(x - 1) = x^2 - 2x + 1[/tex]

AREA OF RECTANGLE

[tex]x(x - 2) = x^2 - 2x[/tex]

Using this we know that the difference is 1, so B is incorrect. We also know that D and E are correct because we solved for the area. C is also wrong, by the same reasoning. Now, all we need to see is if A is right. Plug in x = 2.

[tex](2)^2 - 2(2) + 1 \\= 4 - 4 + 1 \\= 1[/tex]

Because the area of the square is a square unit larger than the rectangle, the rectangle would have an area of 0, which is impossible, so A is correct.

Answer:

400w + 10x

I have no idea what I'm doing

Answer:

  x = 2

Step-by-step explanation:

The two points have the same x-coordinates, so lie on the same vertical line:

  x = 2

The total amount of debt is $119,340.

The total debt to total assets ratio is a financial ratio. It is the ratio of total debt to total asset. It also known as the total debt ratio

Total debt ratio = total debt / total asset

total debt = value of the ratio x value of the assets

0.51 x $234,000 = $119,340

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Answer:

Colinear points: Points that lie on the same line.

Coplanar points: Points that lie in the same plane.

Plane: a flat, 2D surface with no height.

1.  Three colinear points:  A, B, E

2. Four coplanar points: A, B, C, E

3. A plane containing E: plane S

4. Two points and a line that lie in Plane T:  Points F & G, Line L

5. Two planes that contain l:  S and T

Answer:

$ 53,333.33

Step-by-step explanation:

The formula for simple interest is I = PRT. So, we are trying to solve for P(original investment). To do this, we get the formula P = I / RT. This is the formula we will be using.

Work:

First, converting R percent to r a decimalr = R/100 = 5%/100 = 0.05 per year,putting time into years for simplicity,18 months ÷ 12 months/year = 1.5 years,then, solving our equation

P = 4000 / ( 0.05 × 1.5 ) = 53333.333333333

P = $ 53,333.33

Answer:

x=5.11

Step-by-step explanation:

Hi there!

We are given a right triangle (notice the right angle), with one of the angles being equal to 64 degrees

We also know one of the sides is 42, another is x, and the other one is not marked

We want to find the value of x, which we can do using trigonometry

The 3 main trigonometric functions are:
Sine, which is opposite/hypotenuse

Cosine, which is adjacent/hypotenuse

Tangent, which is opposite/adjacent

First, let's find which side is which

The side opposite the 64 degree angle is the opposite; this side is the side marked as 42

The adjacent side would be the other leg (one of the sides creating the right angle); in this case, that would be the side marked as x

The hypotenuse in this case would be the side that hasn't been marked yet

Since we are given values for both the opposite and the adjacent, let's use tangent to find x

Since 64° was the angle we referenced to determine which side was which, we will also make the ratio with this angle.

Therefore, the ratio will be:

[tex]tan(64)=\frac{42}{x}[/tex]

Now we need to solve for x; start by multiplying both sides by x

x * tan(64) = 12

Now divide both sides by tan(64)

x = [tex]\frac{12}{tan(64)}[/tex]

Plug [tex]\frac{12}{tan(64)}[/tex] into your calculator; make sure the calculator is on degree, not radian mode

[tex]\frac{12}{tan(64)}[/tex] ≈ 5.11 (rounded to the nearest hundreth)

So x is about 5.11

Hope this helps!

Topic: trigonometry in right triangles

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Step-by-step explanation:

y=2x find the value of y and x

           - - - - - - - - - - - - - - - - - - - - - - - - - -

[tex]\diamond\large\blue\textsf{\textbf{\underline{\underline{Question:-}}}}\diamond[/tex]

        what is the third angle of a triangle with angles of 45 and 45?

[tex]\diamond\large\blue\textsf{\textbf{\underline{\underline{Answer and How to Solve:-}}}}\diamond[/tex]

      Angles in a triangle always add up to [tex]\bold{180\textdegree}[/tex].

❖ Here we are given 2 angles:-

45 and 45, which add up to 90.

❖  Subtract 90 from 180:-

90

✶ So the angles are 45, 45 and 90.

         - - - - - - - - - -- - - -  - - - - - - -- - - - - - - - -  -

Answer:

90 degrees.

Step-by-step explanation:

As there are 180 degrees in a triangle

third angle = 180 - 45 - 45 = 90 degrees.

To rewrite a word equation as a numerical equation, we can recognize certain keywords and change them into numbers or operations.

We're given:

To solve for x, isolate the variable:

2(x-6) = 5

2x-12 = 5

2x = 17

x = [tex]\dfrac{17}{2}[/tex]

[tex]\dfrac{17}{2}[/tex]

The 4th term of the geometric sequence whose first term is 3 and the common ratio is 2 is 24.

Suppose the initial term of a geometric sequence is a

and the term by which we multiply the previous term to get the next term is r then the sequence would look like

a, ar, ar², ar³,...., arⁿ

Thus, the nth term of such sequence would be aₙ = a₁ × r⁽ⁿ⁻¹⁾ (you can easily predict this formula, as for the nth term, the multiple r would've multiplied with initial terms n-1 times).

Given the first term of the sequence is 3, while the common ratio is 2, therefore, the fourth term of the geometric sequence can be written as,

aₙ = a₁ × r⁽ⁿ⁻¹⁾

a₄ = 3 × 2⁽⁴⁻¹⁾

a₄ = 3 × 2³

a₄ = 24

Hence, the 4th term of the geometric sequence whose first term is 3 and the common ratio is 2 is 24.

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