32.2 divided by 7.56 use compatible numbers to estimate the quotient

After the release of radioactive material into the atmosphere from a nuclear power plant in a country in 1984, the hay in that

AlexFokin [52]

Answer:

23 days.

Step-by-step explanation:

Let the original amount of radioactive material be 100.

We have been given that the half life of a radioactive material is 8 days. It is safe to feed the hay to cows when 14% of the radioactive isotope remains. We are asked to find the number of days, the farmers need to wait to use the radioactive contaminated hay.

We will use half-life formula to solve our given problem.

$A=a\cdot (\frac{1}{2})^{\frac{t}{h}}$ , where,

A = Amount left after t time,

a = Initial amount,

h = Half-life.

14% of 100 would be 14.

$14=100\cdot (\frac{1}{2})^{\frac{t}{8}}$

$\frac{14}{100}=\frac{100\cdot (0.5)^{\frac{t}{8}}}{100}$

$0.14=(0.5)^{\frac{t}{8}}$

Now, we will take natural log of both sides.

$\text{ln}(0.14)=\text{ln}((0.5)^{\frac{t}{8}})$

Using natural log property $\text{ln}(a^b)=b\cdot \text{ln}(a)$ , we will get:

$\text{ln}(0.14)=\frac{t}{8}\times \text{ln}(0.5)$

$\text{ln}(0.14)=\frac{t\times \text{ln}(0.5)}{8}$

$\frac{\text{ln}(0.14)}{\text{ln}(0.5)}=\frac{t\times \text{ln}(0.5)}{8\times \text{ln}(0.5)}$

$\frac{-1.966112856}{-0.69314718055}=\frac{t}{8}$

$2.836501267=\frac{t}{8}$

$\frac{t}{8}=2.836501267$

$\frac{t}{8}*8=2.836501267*8$

$t=22.6920101377$

$t\approx 23$

Therefore, the farmers need to wait for 23 days.

7 0

3 years ago

Plz help me I really don't know

Alex

The value of the expression would be 16.25 or 16 and 1/4, because when you multiply something by 1/2, you’re basically dividing it by 2, and when you put parentheses next to a number (for example 2(4) ), it means that you’re multiplying it, and when more than one values are in the parentheses, they all get multiplied, basically distributive property.

5 0

3 years ago

Select the correct answer.

vivado [14]

Answer:

B will be the answer...

Step-by-step explanation:

The second equation in system B is only in terms of y, so we need to use elimination to eliminate the x term from the second equation in system A.

To do that, we need to multiply the first equation by 5.

5 (-x − 2y = 7)

-5x − 10y = 35

Add to the second equation. Notice the x terms cancel out.

(-5x − 10y) + (5x − 6y) = 35 + (-3)

-16y = 32

Combining this new equation with the first equation from system A will get us system B.

-x − 2y = 7

-16y = 32

4 0

2 years ago

Please help ill give brainliest, explain the answer too please

LiRa [457]

Answer:

4x^2+3x+4

Step-by-step explanation:

3x^2+2x+3+x^2+x+1=4x^2+3x+4

Please give me brainliest.

8 0

3 years ago

Graph The function f(x) = |2x −4|

Aliun [14]

Answer:this is an absolute value function is there more to the question

Step-by-step explanation:

8 0

3 years ago

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