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!!
Answer:
A -60i - 14j
Step-by-step explanation:
u = -9i + 8j
v = 7i + 5j
2u = 2(-9i + 8j) = -18i + 16j
6v = 6(7i + 5j) = 42i + 30j
2u - 6v
(-18i + 16j) - (42i + 30j)
(-18i - 42i) + (16j-30j)
-60i - 14j
Answer:
9375
Step-by-step explanation:
Answer:
84.5
Step-by-step explanation:
(9.9 × 10) ÷ 2= 49.5 (7×10)÷2 = 35
35+49.5 = 84.5