The radioactive compound 14CO2 may be used as a tracer to study metabolism in plants. Suppose that a compound isolated from a plant exhibited 28, 32, 27, 39 and 40 counts of radioactive decays per minute. A blank sample used to measure the background counts of the radiation counter gave 28,21, 28 and 20 counts per minute. It appears that the isolated compound gives more counts than those from background. Can we be 95% confident that the compound is indeed radioactive?​

You likely mean to write the differential equation,

y'' - 2y' + y = exp(x)

The homogeneous part

y'' - 2y' + y = 0

has characteristic equation

r² - 2r + 1 = (r - 1)² = 0

with a root at r = 1 with multiplicity 2, so the characteristic solution is

y = C₁ exp(x) + C₂ x exp(x)

For the particular solution, we assume an ansatz

y = ax² exp(x)

where a is an unknown constant. Differentiating the ansatz twice:

y' = ax² exp(x) + 2ax exp(x) = (ax² + 2ax) exp(x)

y'' = (ax² + 2ax) exp(x) + (2ax + 2a) exp(x) = (ax² + 4ax + 2a) exp(x)

Substitute y and its derivatives into the DE:

(ax² + 4ax + 2a) exp(x) - 2 (ax² + 2ax) exp(x) + ax² exp(x) = exp(x)

Solve for a :

(ax² + 4ax + 2a) - 2 (ax² + 2ax) + ax² = 1

2a = 1

a = 1/2

Then the particular solution is

y = 1/2 x² exp(x)

The general solution is then

y = C₁ exp(x) + C₂ x exp(x) + 1/2 x² exp(x)

Answer:

2 1/2 hours

Step-by-step explanation:

For 1 hour, it would travel 90 miles.

For half of 90 which is 45 it would travel 1/2 hr.

225-180 is 45 miles, which is another half hr.

2 hrs plus 1/2 hr is 2 1/2 hours.

Answer:

x³ - 4x² + 2x + 4 = 0

Here's how I solved this:

You start off by rewriting the zeros into factors:

1 - √3    →    x = 1 - √3    →    (x - 1 - √3)

  2        →    x = 2           →    (x - 2)

1 + √3   →    x = 1 + √3   →    (x - 1 + √3)

Now you want to multiply the factors together:

     (x - 1 - √3) · (x - 2) · (x - 1 + √3)

- Multiply the first two factors together -

                (x - 1 - √3) · (x - 2)

                              ↓

    (x · x - x · 2 - √3 · x + √3 · 2 - x + 2)

   - Combine like terms and simplify -

    (x · x - x · 2 - √3 · x + √3 · 2 - x + 2)

                              ↓

          (x² - 3x - √3 · x + 2√3 + 2)

      - Now multiply the third factor -

   (x² - 3x - √3 · x + 2√3 + 2)(x - 1 + √3)

                              ↓

(x² · x + x² · √3 - x² - 3x · x - 3x · √3 + 3x - √3 · xx - √3 · x · √3 +√3 · x + 2 · √3 · x + 2 · √3 · √3 - 2 · √3 + 2x + 2 · √3 - 2)

                              ↓

(x³ + x² · √3 - x² - 3x² - 3x · √3 + 3x - √3 + 3x - √3 * x² - x · 3 + √3 · x + 2 · √3 · x + 2 · 3 - 2 × √3 + 2x + 2 √3 - 2)

   - Combine like terms and simplify -

(x³ + x² · √3 - x² - 3x² - 3x · √3 + 3x - √3 + 3x - √3 * x² - x · 3 + √3 · x + 2 · √3 · x + 2 · 3 - 2 × √3 + 2x + 2 √3 - 2)

                              ↓

                 x³ - 4x² + 2x + 4

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

And there we get our solution: x³ - 4x² + 2x + 4  

Answers;

Question 1 answer: The first and last option.

Question 1 explanation: 2(4x + 2) is 4x = 12 = 2 = 14 x 2 = 28 and 8x + 4 is 8 x 4 = 32 + 4 = 36 which is 8 more than 28 then, 3x = 9 + 2 + 3 x 2 = 28.

2(4x + 2) = 28 and 8x + 4 equals 36 which is 8 more and they're both equivalent to 2(3x + 2 + x) because 2(3x = 2 = x) equals 28.

Answer:

5x+12+x'

_______

2x'-2x-4

'=2

Answer:

$2,139 was the total amount the school raised.

Step-by-step explanation:

35% of 600= 210

210+600 = $810

10% of 810= 81

810-81= $729

6th Graders= $600

7th Graders= $810

8th Graders= $729

The cost of each bag of apple is $6.35

If Miguel buys eggs and apples at the store.

• He pays a total of $56.97.

• He pays a total of $6.17 for the eggs.

• He buys 8 bags of apples that each cost the same amount

The correct equation that represents the statement will be given as:

Make x the subject of the formula

8x = 56.97 - 6.17

8x = 50.8

x = 50.8/8

x = 6.35

Hence the cost of each bag of apple is $6.35

Learn more on equations here: https://brainly.com/question/2972832

Answer:

14.9

Step-by-step explanation:

50-5.03 = 44.97

44.97 ÷ 3 = 14.99

Answer:

y-9=2(x-3)

Step-by-step explanation:

y-y1=m(x-x1)

y-9=2(x-3)

Hey there!

3(4 - 5x) = 3(4x + 3)

3(4) + 3(-5x) = 3(4x) + 3(3)

12 - 15x = 12x + 9

-15x + 12 = 12x + 9

SUBTRACT 12x to BOTH SIDES

-15x + 12 - 12x = 12x + 9 - 12

SIMPLIFY IT!

-27x + 12 = 9

SUBTRACT 12 to BOTH SIDES

-27x + 12 - 12 = 9 - 12

CANCEL out: 12 - 12 because it gives you 0

KEEP: 9 - 12 because it helps solve for the x-value

NEW EQUATION: -27x = 9 - 12

SIMPLIFY IT!

-27x = -3

DIVIDE -27 to BOTH SIDES

-27x/-27 = -3/-27

CANCEL -27/-27 because that gives you 1

KEEP: -3/-27 because it helps solve for the x -value

NEW EQUATION: x = -3/-27

SIMPLIFY IT/REDUCE the FRACTION!

x = 1/9

Therefore, your answer is: x = 1/9

Good luck on your assignment and enjoy your day!

~Amphitrite1040:)

Answer:

64 tea bags for 9.28

Step-by-step explanation:

Answer:

3 dregreess 5 degrees temperature

Answer:

each cup would cost $0.52

Step-by-step explanation:

there are 16 cups in 1 gallon so you multiply that by two. Then you have 32 so you divide 16.64 by 32 and you end up with 0.52.   hope this helped :))

Tell me I got this wrong

[tex]0 - (-\frac{31}{43})=0+ \frac{31}{43}=\frac{31}{43}[/tex]

ANSWER : true

ok done. Thank to me :>

Answer:

True

Step-by-step explanation:

[tex]0 - ( - \frac{31}{43} ) \\ 0 + \frac{31}{43} \\ = \frac{31}{43} [/tex]

Step-by-step explanation:

This is in the form of

[tex]h(x) = y[/tex]

in this case, x is 1 and y is 7. So ourbpoint would be (1,7.)

Answer:

  10 ml, 0.1 l, 15 cl, 0.5 l, 1000 ml

Step-by-step explanation:

m is an SI prefix for milli-, meaning 1/1000.

c is an SI prefix for centi-, meaning 1/100.

Expressed in liters, these volumes are ...

  0.10 l

  0.50 l

  1000/1000 l = 1.00 l

  10/1000 l = 0.01 l

  15/100 l = 0.15 l

In order from smallest to largest, they are ...

  0.01 l, 0.10 l, 0.15 l, 0.50 l, 1.00 l

In the original units, the order is ...

  10 ml, 0.1 l, 15 cl, 0.5 l, 1000 ml

Answer:

(-4,-5)

Step-by-step explanation:

The coordinates of the midpoint for x = sum of x/2=2

The coordinates of the midpoint for y = sum of y/2=-2

firstly to work out x coordinate:

[tex] \frac{x + 8}{2} = 2[/tex]

rearrange to find x which is -4

work out y coordinate:

[tex]\frac{y + 1}{2} = - 2[/tex]

rearrange to find y which is -5

so coordinates are (-4,-5)

Answer:

I think it is 249 for the first one and the second one i dont know sorry

Step-by-step explanation:

The area of the forest in square yards is [tex]9.3 \times 10^6[/tex]

The area of the forest in square miles is given as:

[tex]Area = 3mi^2[/tex]

To convert the area to square yards from square miles, we multiply the area by 3.098 * 10^6.

So, we have:

[tex]Area = 3 \times 3.098 \times 10^6yd^2[/tex]

Evaluate the product

[tex]Area = 9.294 \times 10^6yd^2[/tex]

Approximate

[tex]Area = 9.3 \times 10^6yd^2[/tex]

Hence, the area of the forest in square yards is [tex]9.3 \times 10^6[/tex]

Read more about areas at:

https://brainly.com/question/24487155

Answer:

8

Step-by-step explanation:

diameter is the radius times 2

Answer:

8/10

Step-by-step explanation:

id hope your have a great day

Answer:

80%

Step-by-step explanation:

80÷100=.8 which is 80%

Using the percentage concept, it is found that the San Francisco Giants won 46.3% of their games.

The percentage of an amount a over a total amount b is given by a multiplied by 100% and divided by b, that is:

[tex]P = \frac{a}{b} \times 100\%[/tex]

In this problem:

Then:

[tex]P = \frac{75}{162} \times 100\% = 46.3\%[/tex]

The San Francisco Giants won 46.3% of their games.

You can learn more about the percentage concept at https://brainly.com/question/10491646

Answer:

a=35 b=14 c=5

Step-by-step explanation:

a

180-55-90=35

b

b+6=20

b=14

c

4c-6=14

14+6=20

20/4=5

27) 115=5(5a-2)

115= 25a-10

125=25a

a=5

28) -72=-x-6(x+5)

-72=-7x-30

-42=-7x

x=6

i did two of them. now i gtg so won't do the rest

There is a total of 52 grams of carbs in 1/4 cup, then 1 tablespoon will contain 208 grams of carbs.

The four fundamental operations of arithmetic are addition, subtraction, multiplication, and division of two or even more items.

Included in them is the study of integers, especially the order of operations, which is important for all other areas of mathematics, notably algebra, data management, and geometry.

As per the given information in the question,

There are 52 grams of carbs in 1/4 cup of syrup

Let's assume that the amount of carbs in 1 tablespoon is x.

So,

x = (52 × 4)

x = 208 grams.

To know more about arithmetic operations:

https://brainly.com/question/25277954

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