<span>The answer is 9,990 years. Using the exponential decay question, we can figure out how long it will take Plutonium-240 to decay from 27 grams to 9 grams. Setting the equation up looks like this, 9 = 27 e^ (-0.00011 t). From this you get, 0.333333 = e ^(-0.00011 t). Next, you simplify by dividing both sides by the natural log, -1.0986 = -0.00011 t. Finally, you solve by dividing both sides by -0.00011, giving 9,987 years for t, rounded up to 9,990 years.</span>

7 0

3 years ago

Read 2 more answers

Please answer correctly !!!!! Will mark brainliest answer !!!!!!!!!!

AnnZ [28]

Answer:

type 2 in the first box,

13/4 in the second box, and

-9/8 in the third one

Step-by-step explanation:Notice that you are asked to write the following quadratic expression in vertex form, so you need to find the "x" value of the vertex, and then the "y" value of the vertex:

$x_{vertex}= -b/2a$

Which in our case is: -13/4

and the value of the y for the vertex is obtained using the functional expression when x equals -13/4:

$f(-13/4)= -9/8$

Then your expression for this quadratic should be:

$f(x)=2\,(x+\frac{13}{4} )^2+(-\frac{9}{8})$

Then type 2 in the first box, 13/4 in the second box, and -9/8 in the third one

7 0

3 years ago

A shelter in the city house birds and dogs . There are 25% more dogs then birds. If there are 50 birds how many dogs are there?

AfilCa [17]

Answer:

They have 83 dogs and 50 birds.

There are 133 animals in total in the shelter.

Step-by-step explanation:

So let's call the dogs D and the birds B.

D = 25% + B

What ever the amount of animals, the total for D must always be 25% more than B.

To get 100% of the animals, B must equal 37.5% and D must equal 62.5%.

The way I worked this out was:

100% - 25%= 75%

75% divided by 2= 37.5%

37.5% + 25%= 62.5%

And just to check

37.5% + 62.5% = 100%

So to work out 100%:

37.5% = 50

divide both by 37.5 to get 1%

1% = 1.333333

time both by 62.5 to get 62.5%

62.5% = 83.333313

We'll round that answer because I'm pretty sure they don't have a .333313th of a dog.

So D = 62.5% = 83

They have 83 dogs and 50 birds.

Phew! That was the hard part. Now onto something wayyy easier.

To get the total number of animals in the shelter we just do 83 + 50, which is 133.

There are 133 animals in total in the shelter.

Hope this helps you :)

7 0

3 years ago