Answer:
my teacher gave me the exact answer for this
Step-by-step explanation:
Answer:
81
Step-by-step explanation:
9^2 = 81 bc 9x9=81
Answers:
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Explanation:
Part (a)
Lines LN and PN have the point N in common. This is the intersection point.
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Part (b)
To name a plane, pick any three non-collinear points that are inside it. We cannot pick points H, J, K together because infinitely many planes pass through it. Imagine the piece of flat paper able to rotate around this axis (like a propeller). Having the points not all on the same line guarantees we form exactly one unique plane.
I'll pick the non-collinear points P, H and J to get the name Plane PHJ. Other answers are possible.
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Part (c)
Points H, J and K are collinear as they are on the same line. Pick either H or K to fill out the answer box. I'll go with point K
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Part (d)
Point P and line HK are coplanar. They exist in the same flat plane, or on the same sheet of flat paper together.
We can think of that flat plane as the ground level while something like point N is underground somewhere. So point N and anything on that ground plane wouldn't be coplanar.
Note: there are other possible names for line HK such as line JH or line JK. The order doesn't matter when it comes to naming lines.
Answer:
b=8
Step-by-step explanation:
b=√(10²-6²)=√(100-36)=√64=8
Answer:
8978 grams
Step-by-step explanation:
The equation to find the half-life is:

N(t) = amount after the time <em>t</em>
= initial amount of substance
t = time
It is known that after a half-life there will be twice less of a substance than what it intially was. So, we can get a simplified equation that looks like this, in terms of half-lives.
or more simply 
= time of the half-life
We know that
= 35,912, t = 14,680, and
=7,340
Plug these into the equation:

Using a calculator we get:
N(t) = 8978
Therefore, after 14,680 years 8,978 grams of thorium will be left.
Hope this helps!! Ask questions if you need!!