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3 years ago

After 3 days a sample of radon-222 has decayed to 58% of its original amount.

1 answer:

6 0

The half-life of the radioactive substance can be determined through teh equation ln 2 = k (t 1/2) where k is equal to ln (1/(1-0.58)) / 3. Hence t 1/2 is equal to 2.40 days. To decay to 10% of the original amount, ln (1/0.90) / ( ln2) / 2.40, time is equal to 0.37 days.

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0.13x0.11=????????????????

andre [41]

Answer:

0.0143 in decimal form

Step-by-step explanation:

3 0

3 years ago

Solve for x.<br><br> 8x^2−3=2

sergeinik [125]

8x^2=2+3

8x^2=5

x^2=5/8

x= sqrt(5/8)

5 0

3 years ago

Rounded to the nearest hundredth, what is the positive solution to the quadratic equation 0 = 2x2 + 3x – 8? Quadratic formula: x

Lynna [10]

ANSWER

1.39

EXPLANATION

The given quadratic equation is

$0 = 2 {x}^{2} + 3x - 8$

This is the same as,

$2 {x}^{2} + 3x - 8 = 0$

Comparing to

$a {x}^{2} + bx + c = 0$

We have

a=2, b=3,c=-8

Using the quadratic formula, the solution is given by:

$x = \frac{ - b \pm \: \sqrt{ {b}^{2} - 4ac} }{2a}$

We substitute the values to get,

$x = \frac{ - 3\pm \: \sqrt{ {3}^{2} - 4(2)( - 8)} }{2(2)}$

$x = \frac{ - 3\pm \: \sqrt{ 73} }{4}$

The positive root is

$x = \frac{ - 3 + \: \sqrt{ 73} }{4} = 1.39$

to the nearest hundredth.

4 0

3 years ago

Read 2 more answers

Image attached, please help.

tia_tia [17]

Answer:

B 3x: 51 = 3x+24: 85

Step-by-step explanation:

Since the triangles are similar

PS PQ

------- = -----------

PT PR

Substitute the values in

3x 3x+24

------- = -----------

51 85

3x: 51 = 3x+24: 85

4 0

3 years ago

A right triangle has sides of length 3, 4, and .

olchik [2.2K]

Answer:

5/hypotenuse, the square root of 7/ leg

Step-by-step explanation:

3^2+4^2=25 or 5^2. you use a^2+b^2=c^2. it would be one of the hypotenuses. If the missing number is a leg, you would do 4^2=3^2+x^2. 16=9+x^2, 7=x^2, so you plug in the numbers differently.

3 0

3 years ago

Read 2 more answers