A radioactive substance decays exponentially: The mass at time t is m(t) = m(0)e^kt, where m(0) is the initial mass and k is a negative constant. The mean life M of an atom in the substance is
[infinity]
M = âk â« te^kt dt.
0

For the radioactive carbon isotope, 14C, used in radiocarbon dating, the value of k is -0.000121. Find the mean life of a 14C atom.

Answer:

1) akram : shazia

20-4 : 15-4

16 : 11

2) akram : shazia

20 + 5 : 15 + 5

25 : 20

5 : 4

3) ratios are not always constant

Answer:

6 hours.

Step-by-step explanation:

x = supervisor's hours alone

Since there are two people working together, you need to incorporate some kind of 2 in this problem.

If the postal worker was cloned, it would take 4 hours.

3 x 2 = 6.

let the line between 2 tria be y

sin 60/8√2 = sin 90/y

y=13.06

sin 45/13.06 = sin 90/x

x=18.46

Answer:

First, find the hypotenuse of the right triangle with the 60° & 30°.

[tex]sin(60) = \frac{8\sqrt{2}}{h} \\\\sin(60)h=8\sqrt{2}\\\\\frac{\sqrt{3}}{2} h=8\sqrt{2}\\\\h=\frac{8\sqrt{2}}{\frac{\sqrt{3}}{2}}=8\sqrt{2}*\frac{2}{\sqrt{3}} =\frac{16\sqrt{2} }{\sqrt{3}} =\frac{16\sqrt{2}(\sqrt{3}) }{\sqrt{3}(\sqrt{3})} =\frac{16\sqrt{6} }{3}[/tex]

Use that side length to find x.

[tex]sin(45)=\frac{\frac{16\sqrt{6}}{3}}{x}\\\\sin(45)x=\frac{16\sqrt{6}}{3} \\\\\frac{\sqrt{2}}{2}x=\frac{16\sqrt{6}}{3} \\\\x=\frac{\frac{16\sqrt{6}}{3}}{\frac{\sqrt{2}}{2}}=\frac{16\sqrt{6}}{3}*\frac{2}{\sqrt{2}}=\frac{16\sqrt{2}\sqrt{3}(2)}{3\sqrt{2} }=\frac{32\sqrt{3} }{3}[/tex]

Answer:

You have to follow PEMDAS or parenthesis, exponents, multiplication, division, addition, and subtraction. It's an order to solve equations. I listed the steps and the answers for you below :) I have throughly checked them so they should be correct! yw :D

Step-by-step explanation:

1. 5x + 4x - 6x = 24

9x - 6x = 24

3x = 24

24/3 = 8

x = 8

2. 8y + 5 - 4y + 1 = 46

8y - 4y = 4y

5 + 1 = 6

4y + 6 = 46

4y = 46 - 6

4y = 40

40/4 = 10

y = 10

3. 33 = 5 ( x + 8 ) + 3

33 =  5x + 40 + 3 (because we distributed)

33 = 5x + 43

5x + 43 = 33 (just rewriting it to make it easier)

5x = 33 - 43

5x = -10

-10/5 = -2

so x = - 2

4. 2m + 3 ( m - 8 ) = 1

2m + 3m - 24 = 1

we got 3m - 24 because we distributed the 3

5m - 24 = 1

5m = 25

25/5 = 5

m = 5

5. p + p - 2p + 4p = - 48

2p - 2p + 4p = - 48

4p = - 48

- 48 / 4 = - 12

p = - 12

6. 2 ( y + 5 ) + 3y = 25

2y + 10 + 3y = 25

5y + 10 = 25

5y = 25 - 10

5y = 15

15/5 = 3

y = 3

7. 1/4 h + 3/4 h + 1/2 h + 2 = 5

1/4 h + 3/4 h + 1/2 = 3/2 h

3/2 h + 2 = 5

3/2 h = 5 - 2

3/2 h = 3

h = 2

8. 60 = 4 ( k + 3 ) + 2 ( k - 3 )

60 = 4k + 12 + 2k - 6

4k + 12 + 2k - 6 = 60

6k + 6 = 60

6k = 60 - 6

6k = 54

k = 9

9. - 2 ( d + 1.4 ) - 1.8 = 20.6

-2d + - 2.8 - 1.8 = 20.6

-2d - 2.8 = 22.4

-2d = 25.2

d = - 12.6

10. 8 - 2 ( w + 4 ) = 10

8 + - 2 w + - 8 = 10

-2w + 9 + - 8 = 10

-2w = 10

10 / -2 = -5

w = -5

9514 1404 393

Answer:

  38.1% decrease

Step-by-step explanation:

A percentage change is found from ...

  % change = (change)/(original amount) × 100%

  = (new value - original amount)/(original amount) × 100%

  = (13 -21)/21 × 100% = -8/21 × 100% ≈ -38.1%

Frazer's speed decreased by 38.1% during the second part.

_____

Additional comment

A negative % change represents a decrease; a positive % change represents an increase.

Answer:

The answer is 1,000

SInce the beginning number is 3 and there are ten possible numbers to put in the remaining three slots, there are exactly 1,000 possible combinations for a 3-digit code. The answer is 1,000. There are 3 rows of 10 digits. The number of combinations 10 to the thid power which is 1000 (10 * 10 * 10)

Answer: About 63 in²

Step-by-step explanation:

Area of circle = π · r²

Area of large pizza:

[tex]\pi *r^{2} =3.14*6^{2} =3.14*36=113.04[/tex]

Area of small pizza:

[tex]\pi *r^{2} =3.14*4^{2} =3.14*16=50.24[/tex]

Difference in area:

[tex]113.04-50.24=62.8[/tex]

Answer:

Step-by-step explanation:

Answer:

By the Sum Rule, the derivative of 1−sin(x) 1 - sin ( x ) with respect to x x is ddx[1]+ddx[−sin(x)] d d x [ 1 ] + d d x [ - sin ( x ) ] .

Answer:

Differentiation is concerned with things like speeds and accelerations, slopes and curves ect. These are Rates of Change, they are things that are defined locally. The Fundamental Theorem of Calculus is that Integration and Differentiation are the inverse of each other.

Answer:

[tex]{ \sf{ \underline{ {x}^{2} + 5x - 6 }}}[/tex]

Step-by-step explanation:

[tex](x + 6)(x - 1) \\ = {x}^{2} - x + 6x - 6 \\ = {x}^{2} + 5x - 6[/tex]

Answer:

C

Step-by-step explanation:

one line is

y = 3x/7 + 11

its slope is 3/7

the y-intercept is, of course, when x=0. there y=11

the other is

-3x + 7y = 13

7y = 3x + 13

y = 3x/7 + 13/7

its slope is 3/7 (the same as the other line)

the y-intercept (x=0) is y = 13/7 (different to the other line)

Answer:

C. Yes, since the slopes are the same and the y-intercepts are different.

Step-by-step explanation:

[tex]y=\frac{3}{7} x+11[/tex]  and [tex]-3x+7y=13[/tex]

→ Rearrange the second equation to make y the subject

7y = 3x + 13

→ Divide everything by 7

[tex]y=\frac{3}{7} x+\frac{13}{7}[/tex]

Answer: 4,989,600 different ways

Step-by-step explanation:

G(x)=5x+3

[tex]\\ \sf\longmapsto G(2)[/tex]

[tex]\\ \sf\longmapsto 5(2)+3[/tex]

[tex]\\ \sf\longmapsto 10+3[/tex]

[tex]\\ \sf\longmapsto 13[/tex]

Option c is correct

Answer:

The student took the numbers for the factors 5, -4 for the zeros  instead of solving the equation

The zeros are -5, 4

Step-by-step explanation:

x^2 +x - 20=0

What 2 number multiply to -20 and add to 1

5*-4 = -20

5+-4 = 1

(x+5)(x-4) =0

Using the zero product property

x+5 = 0  x-4 =0

x=-5  x=4

Answer:

Solution given:

equation is:

x²+x-20=0

doing middle term factorisation

note:we need to get 1 while subtracting factor of the product of constant and coefficient of x².

20*1=20=2*5*2*1

we get 1 while subtracting 5-2*2=5-4

now substitute value 5-4 at coefficient of x

we get

x²+(5-4)x-20=0

now

distribute

x²+5x-4x-20=0

taking common from each two term

x(x+5)-4(x+5)=0

again taking common (x+5) and keeping remaining at another bracket

(x+5)(x-4)=0

either

x+5=0

x=-5

or

x-4=0

x=4

Error is:

x= 4 not -4

x=-5 not 5.

Answer:

3.2 hours

Step-by-step explanation:

12 workers * 4 hours = 48 worker hours

15 workers  * x hours = 48 worker hours

48 /15 =3.2 hours

Answer:

3 hours and 12 minutes.

Step-by-step explanation:

12 Workers complete a job in 4 hours

1 worker complete a job 12 × 4 = 48

15 workers complete a job = 48/15 = 3³/¹⁵ = 3¹/⁵

= 3 hours + 1/5 × 60  minutes = 3 hours 12 minutes.

Answer:

The 95% confidence interval for the mean of mid-upper arm circumference based on your sample is between 139.29 mm and 160.71 mm.

Step-by-step explanation:

We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.

The first step to solve this problem is finding how many degrees of freedom,which is the sample size subtracted by 1. So

df = 4 - 1 = 3

90% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 3 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.95}{2} = 0.975[/tex]. So we have T = 3.1824

The margin of error is:

[tex]M = T\frac{s}{\sqrt{n}} = 3.1824\frac{6.73}{\sqrt{4}} = 10.71[/tex]

In which s is the standard deviation of the sample and n is the size of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is 150 - 10.71 = 139.29 mm

The upper end of the interval is the sample mean added to M. So it is 150 + 10.71 = 160.71 mm

The 95% confidence interval for the mean of mid-upper arm circumference based on your sample is between 139.29 mm and 160.71 mm.

Answer:

35 cm

Step-by-step explanation:

You can use the Cosine Rule to find the length of a side when two sides and the included angle are given.

a² = b² + c² - 2bc cos A

a² = (36²) + (52²) - 2(36)(52) cos 42°

a² = (1296) + (2704) - (3744)(0.7431448255)

a² = (4000) - (2782)

a² = 1218

a = ✓1218

a = 34.9 cm

Answer:

150 e udi,auwdbkhg

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8ઈઘુઘ

Answer:

39/250

Step-by-step explanation:

15 3/5 = 78/5 and percent means per 100, so

(78/5)/100 = (78/5)(1/100)

=78/500 = 39/250

Answer:

z -2 = 10

Step-by-step explanation:

11z-9-10z+7 = 10

Combine like terms on the left side

11z -10z     -9+7  =10

z -2 = 10

Answer: z=12

Step-by-step explanation:

[tex]11z-9-10z+7=10\\z-9+7=10\\z-2=10\\z=12[/tex]

Answer:

You’ve worked 7 hours and 30 minutes

Step-by-step explanation:

Answer:

A. [tex]\frac{5}{13}[/tex]

Step-by-step explanation:

Hi there!

We are given right triangle PQR, with PR=5, RQ=12, and PQ=13

We want to find the value of sin(Q)

Let's first recall that sine is [tex]\frac{opposite}{hypotenuse}[/tex]

In reference to angle Q, PR is the opposite side, RQ is the adjacent side, and PQ is the hypotenuse

So that means that sin(Q) would be [tex]\frac{PR}{PQ}[/tex]

Substituting the values of PR and PQ gives sin(Q) as [tex]\frac{5}{13}[/tex], which is A

Hope this helps!

9514 1404 393

Answer:

Step-by-step explanation:

The result each should have obtained is ...

  a +10 = 17

  a = 7

Braulio's mistake was in using 1 as his divisor instead of -1. His bottom row should have been 1, 4, a-4, 1-a, a +10.

Zahra's mistake was improperly evaluating higher powers of -1. Her evaluation should have been 1 -5 +a +3 +11 = a +10.

Answer:

2x^5-10x^4-8x^3

Step-by-step explanation:

2x^3 ( x^2 - 5x-4)

Distribute

2x^3 * x^2  - 2x^3 -5x  -2x^3 *4

2 x^(3+2) - 10 x^(3+1) - 8x^3

2x^5-10x^4-8x^3

Answer:

how did not orderstan that

9514 1404 393

Answer:

  x = 100°

  y = 95°

Step-by-step explanation:

It is probably easier to find y first. Opposite angles of an inscribed quadrilateral are supplementary, so ...

  y = 180° -85° = 95°

The measure of an arc is double the measure of the inscribed angle subtending it. The arc subtended by angle y is ...

  90° +x = 2y

  x = 190° -90° = 100°

_____

Additional comment

The rule cited above regarding opposite angles of an inscribed quadrilateral comes from the theorem regarding inscribed angles. In the given diagram, the diagonal from the bottom vertex to the top one is a chord that divides the circle into two arcs. Their sum is 360°. The inscribed angle theorem tells you ...

  2y +2(85°) = 360°

  y + 85° = 180° . . . . . . . divide by 2; opposite angles are supplementary

Answer:

both

Step-by-step explanation:

Congruent shapes have equal corresponding side lengths

The true statement is (c) both

To map the quadrilaterals on one another, then the sequence of transformation must be rigid transformation

The given sequence of transformations are both rigid, and they both would map quadrilaterals STUV and ABCD

Hence, the true statement is (c) both

Read more about transformation at:

https://brainly.com/question/4289712