The half life of a radioactive substance is 10 years. If 64 grams are placed in a
container, how much will remain after 50 years?

Answer:

Step-by-step explanation:

The coefficients of x and y do not have any "nice" relations, so doing this by elimination is just "brute force" with no particular subtlety.

After multiplying by appropriate numbers, you want the coefficient of one of the variables in one equation to be the opposite of the coefficient of the same variable in the other equation. Here, we can get that by multiplying the first equation by 7 and the second equation by 2.

  7(2x +3y = -19)   ⇒   14x +21y = -133

  2(-7x +2y = -21)   ⇒   -14x +4y = -42

Adding these equations with opposite x-coefficients eliminates the x-terms. (That is how the "elimination" method gets its name.)

  (14x +21y) +(-14x +4y) = (-133) +(-42)

  25y = -175 . . . . . . . . simplify

  y = -7 . . . . . . . . . . . divide by 25

Substituting this value into the first equation gives ...

  2x +3(-7) = -19

  2x = 2 . . . . . . . . . add 21

  x = 1 . . . . . . . . . divide by 2

The solution is x = 1, y = -7.

_____

Additional comment

The multipliers used in this process are essentially the coefficients of one of the variables, with one of them negated. Here, we chose the x-coefficients, because negating one of them gives two positive multipliers. We judge it easier to do the arithmetic using positive numbers.

Had we chosen to use the y-coefficients (3 and 2) for our multipliers, we would probably multiply the first equation by 2, and the second equation by -3. That way, the remaining x-coefficient would be positive.

Planning ahead is helpful, but not essential. It can help to avoid errors and make the work easier to do.

Answer:

x = 20, y = 10

Step-by-step explanation:

Triangle RTS is isosceles. You can tell because both of the base angles have the same measure. That means that RT must also be 15. Triangle UTR is equilateral because all 3 angles have the same measure. UT is x - 5 and is equal to RT which is 15, so x - 5 = 15, and x is 20.

Since triangle UTR is equilateral, angle URT is 60 degrees. Angle SRT is linear with angle URT, so angle SRT is 120 degrees. That means the other 2 angles must add to 60 degrees, making each one worth 30 degrees. Angle RTS says 3y, so 3y =30, and y = 10

Answer:

To Bend I would say.

Step-by-step explanation:

Because he wants to get out of the stituration and go to the arcade. But he needs to change he father's mind to go. So he needs to Bugde or Bend his father's decision to let him go to the arcade.

Answer:

Step-by-step explanation:

A 45-45-90 right triangle is isosceles. That means both legs are the same length, and its hypotenuse is √2 times the leg length. You can figure these facts using trigonometry or the Pythagorean theorem, or you can rely on your memory of them.

w = 8 . . . . . . . . . . . same as the leg length shown

x = y = 8√2 . . . . . hypotenuse of smaller triangle; both legs are the same

z = (8√2)√2 = 16 . . . . hypotenuse of larger triangle

Answer:

$1.13

Step-by-step explanation:

You multiply 0.15*7.5, and you get 1.125, which you add up to $1.13

Answer:

maybe (-3,-4)?

Step-by-step explanation:

Answer:

A) 0

Step-by-step explanation:

15/21 simplifies to 5/7. 5/7-5/7 (itself) is 0.

Answer:

0

Step-by-step explanation:

= [tex]\frac{5}{7}-\frac{5}{7}[/tex]

= [tex]\frac{5-5}{7}[/tex]

= [tex]\frac{0}{7}[/tex]

= [tex]0[/tex]

Answer:

I need the photo

Step-by-step explanation:

I need the photo

Transformation involves changing the form of a function

The true statement is (a) it is stretched horizontally by a factor of 2 and translated up, 3 units.

The function is given as:

[tex]y = \log(x)[/tex]

Start by stretching the graph of [tex]y = \log(x)[/tex], horizontally by a factor of 2.

So, we have:

[tex]y = \log(2 \times x)[/tex]

[tex]y = \log(2x)[/tex]

Next, shift the function up by 3 units.

So, we have:

[tex]y = \log(2x) + 3[/tex]

Hence, the true statement is (a)

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Answer:

its b on edge

Step-by-step explanation:

Answer:

25 points

Step-by-step explanation:

21 x 3

63

-20

43

-18

25

Given monomials are (3/4)pq , (1/2)qr² , -5p²r³ and -6r⁵

On multiplying them then

⇛ [(3/4)pq]×[(1/2)qr²]×[-5p²r³]×[-6r⁵]

⇛ [(3/4)×(1/2)×(-5)×(-6)]×(pq×qr²×p²r³×r⁵)

⇛[(3×1×-5×-6)/(4×2)](p×p²)×(q×q)×(r²×r³×r⁵)

⇛ (90/8)×p³×q²×r¹⁰

Since a^m × a^n = a^(m+n)

⇛ (45/2)×p³×q²×r¹⁰

⇛( 45/2 ) p³q²r¹⁰

Answer:- [(3/4)pq]×[(1/2)qr²]×[-5p²r³]×[-6r⁵] = (45/2)p³q²r¹⁰

Answer:

[tex]3 - 4 = 1[/tex]

✨✨

3-4

you just need to subtract 3 from -4

so , your answer is -1

Answer:

The answer is the last one: One runner in the study runs 31...

Step-by-step explanation:

31 is the input (x) and 81 is the output (y) and since there's 1 ordered pair per runner, it's going to be one runner, and the input is the miles ran.

The point (31, 81) tells One runner in the study runs 31 miles per week and has a standing heart rate of 81 beats per minute.

In mathematics, data is a collection of facts and figures that can take any shape, whether it be numerical or not. You can calculate numerical data, which is always gathered in number form and includes things like student test results, employee salaries, football team member heights, etc.

Given:

The college track coach conducts a study to see if the number of miles a person runs per week affects the standing heart rate (beats per minute).

So, the point (31, 81) tells that the runner run 31 miles this week with hear rate 81 beats / min

Hence, point (31, 81) tells One runner in the study runs 31 miles per week and has a standing heart rate of 81 beats per minute.

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Answer:

327.25

Step-by-step explanation:

550*0.7=385

385*0.85=327.25

!!! MUST REMEMBER!!!

dont add 30% and 15% together, 15% is another discount on the price that has been marked down.

The final price of a sofa will be $302.5.

What is mean by Percentage?

A number or ratio that can be expressed as a fraction of 100 or a relative value indicating hundredth part of any quantity is called percentage.

To Calculate the percent of a number , divide the number by whole number and multiply by 100.

Given that;

The original price of a sofa = $550

During sale at a furniture store, sofas marked down = 30%

Coupon for an additional 15% off.

Now,

Total percent for profit on a sofa = 30% + 15%

                                                  = 45%

Hence, The cost of a sofa after discount will be calculate as;

The cost of discount at a sofa = 45% of 550

                                              = 45/100 x 550

                                              = 24,750 / 100

                                              = 247.5

So, The final cost of a sofa = $550 - $247.5

                                         = $302.5

Therefore, The final price of a sofa will be $302.5.

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Answer:

pretty sure it's D........

Answer:

127 is the IQR.

Step-by-step explanation:

C: 4

IQR (interquartile range) can be found by subracting Q1 from Q3 (Q3 - Q1)

Reposting because Katie from the Brainly staff seems to think simple subtraction is a violation of community guidelines ¯\_(ツ)_/¯

Answer:

m = 5

Step-by-step explanation:

200m - 125m + 48,750 = 50,000 - 175m​

=> 75m + 48,750 = 50,000 - 175m​

=> 75m + 175m = 50,000 - 48,750

=> 250m = 1250

=> m = 5

Hoped this helped.

Answer:

12.5% and 60%

Step-by-step explanation:

0.125 x 80 = 10

160-64 = 96

96/160 = 0.6

0.6 x 100 = 60%

Answer:

D. ab=ab

Step-by-step explanation:

Communitive property of addition is a number plus a number and the number added to the first number backwards but equal the same answer. For instance (if you don't understand what I'm saying) Look at answer A in your problem, a+b=b+a that's how the communitive property works in addition. The rest of the answer choices also shows communitive property. This is why answer D does NOT show the communitive property in addition.

I'm sorry if I didn't explain right or if I'm wrong but I tried my best. Have a good day and enjoy your answer. I hope you learned something Thanks :)

Step-by-step explanation:

she is the only sales agent selling cars after totaling them ... :-)

she makes 12% commission on the amount of sales beyond $50,000.

so, total sales was $115,000.

the base for her commission is then

115,000 - 50,000 = $65,000

she gets 12% of these $65,000.

100% = $65,000

1% = 100%/100 = 65,000/100 = $650.

12% = 1%×12 = 650 × 12 = $7,800

so, C is the right answer.

Answer:

True

Step-by-step explanation:

1. To find if this statement is true or false, we first have to evaluate the value of these numbers.

2. Next, we divide 30,000 by 6,000. If our quotient is 5, then this is true.

Therefore, this is true.

Answer:

<NLO and <OLN

Step-by-step explanation:

These two angle names are the same. the letters are simply reversed. it's like saying 1+2=3 and 2+1=3. the same. only reversed but still fluent in simplicity.

Answer: A lot

Step-by-step explanation: I can't count how many

Step-by-step explanation:

System of Linear Equations entered :

[1] 2x-y=4 [2] y-x=4

Equations Simplified or Rearranged :

  [1] 2x - y = 4   [2] -x + y = 4

Graphic Representation of the Equations :

y + 2x = 4 y - x = 4

Solve by Substitution :

// Solve equation [2] for the variable  y 

[2] y = x + 4

// Plug this in for variable  y  in equation [1]

  [1] 2x - (x +4) = 4   [1] x = 8

// Solve equation [1] for the variable  x 

  [1] x = 8 

// By now we know this much :

  x = 8   y = x+4

// Use the  x  value to solve for  y 

  y = (8)+4 = 12 

Solution :

 {x,y} = {8,12} 

Answer:

Yes he does.  the total to all those numbers is 1277

Step-by-step explanation:

Answer:

a: -1/2

b: 15

Step-by-step explanation:

A system that has infinite solutions is the same line on top of itself.

Hope that helps

Answer:

Slope: 1/2

Step-by-step explanation:

Look at the file.

Answer: B

Step-by-step explanation:

Answer:

The amount of tax is £178.34, and the full total is £1142.34.

Step-by-step explanation:

Use a calculator to find 18.5 percent of 964, giving us the answer we need. You may add this to the cost before tax to find the exact price after tax.

The amount of tax that is added to the cost of the computer is

£178.34.

A compulsory contribution to state revenue, levied by the government on workers' income and business profits, or added to the cost of some goods, services, and transactions.

Given is that a computer costs £964. A tax of 18.5% is then added to the cost of the computer.

Assume the amount of tax that is added to the cost of the computer is

£{x}. Then, we can write the equation as -

{x} = 18.5% of 964

{x} = (18.5/100) x 964

{x} = 178.34

Therefore, the amount of tax that is added to the cost of the computer is

£178.34.

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