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3 years ago

Iodine-125 has a half-life of about 60 days.

1 answer:

4 0

We know that Iodine - 125 has a half life of 60 days.
300 : 60 = 5 . It means that it was halved 6 times.
Therefore: 500 mg * 0.5^5 =
= 500 mg * 0.5 * 0.5 * 0.5 * 0.5 * 0.5 =
= 500 mg * 0.03125 = 15.625 mg
Answer: 3. 15.625 mg.

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Find the value of k if the distance between (2,k) and (6,7) is 4√2 unit

andreyandreev [35.5K]

Answer:

k = 3

Step-by-step explanation:

We have the distance formula: $d = \sqrt{(x_2-x_1)^2 + (y_2-y_1)^2}$ . We can plug in $4\sqrt{2}$ = d, x2 = 6, x1=2, y2 = 7, y1 = k.

Then, we can solve the question using some algebra to find that k = 3.

Edit: Here is a step by step:

$4\sqrt{2} = \sqrt{(6-2)^2 + (7-k)^2}\\$

$(4\sqrt{2})^2 = (6-2)^2 + (7-k)^2$

$32 = (4)^2 + (7-k)^2$

$32 = 16 + (7-k)^2$

$32 - 16 = (7-k)^2$

$16 = (7-k)^2$

$\sqrt{16} = (7-k)$

$4 = 7-k$

$k = 3$

4 0

2 years ago

How to combine like terms

aev [14]

Example: $1x+2y+3z+4a+5x+6y+7z+8+9$

We can see that there is more than one number with the variable x, therefore, we say they're ''like terms'' and because of that they can be summed. We do this with all of the other numbers with similar variables. If no numbers with similar variables are left, like 4a, you don't do anything but write them as they are. You can also see that 8 and 9 can also be summed because neither of them has a variable, therefore they're similar.

In this step, you just do the operation with the numbers and keep the same variable.

$(1x+5x)+(2y+6y)+(3z+7z)+4a+(8+9)$

$(6x)+(8y)+(10z)+4a+(17)$

since there are not more numbers similar in variables, this operation is done.

$6x+8y+10z+4a+17$

8 0

2 years ago

Keisha throws a rock down an old well the distance D in Feet The Rock Falls after T seconds can be represented by D =16t ^ 2 + 6

sesenic [268]

Answer:

1 second 

Step-by-step explanation:

16t^2+64t=80

16t^2+64t-80=0

64^2-4(16)(-80)

9216

-64-96

______ = -5

 32

-64+96

_______ = 1 sec

 32

7 0

3 years ago

How many different 1-topping pizzas can be formed by choosing a size and topping if your choices for size are small, medium, lar

Rudik [331]

The answer is A. 28

4 0

3 years ago

Read 2 more answers

A truck cost $21,000.00 with an estimated salvage value of $1,000.00. It has an estimated useful life of 5 years. If the truck w

taurus [48]

Straight line depreciation applies the same amount of depreciation in each year.
Our Depreciation Base is 21,000 - 1,000 = 20,000
The useful life is 5 years, so each year we depreciate 20,000 ÷ 5 = 4,000

Book Value is Cost - Accumulated Depreciation
After Year 1:
Book Value = 21,000 - 4,000 = 17,000

Answer is A) 17,000

6 0

2 years ago