20 miles
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brainliest pls?
Answer:
-74.
Step-by-step explanation:
First, notice that we can divide it into 2 equations (1 on each side of the equal symbol).
<h3>1st step:</h3>
Replace where's x by -2 in the left equation:

<h3>2nd step:</h3>
Now, we will replace the squares with 16 in the second equation. Look:

So, the answer is -74.
<h2>We also can solve it in another way:</h2>

Now let's call the gray square as y in the second equation:

So, your final answer is -74.
Hope it helps! :D
Answer:
0.31 0.325 0.35 0.38 0.425 32.5
Step-by-step explanation:
1. Yes, 25 x 25 = 625.
2. No, as the resulting answer is 6.09 rounded.
It takes 16,064 years for the 500g of radium to decay to 5g.
<h3>
How long will it take for 500g of radium to decay to 5g?</h3>
Here we have the decay equation:

Where Q₀ is the initial amount, and k is the decay constant.
We know that:
Q₀ = 500g
k = 0.00043
And we want to find the value of t such that Q(t) = 5g, so we need to solve:

Now we can apply the natural logarithm in both sides:

So it takes 16,064 years for the 500g of radium to decay to 5g.
If you want to learn more about decays:
brainly.com/question/7920039
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