Answer:
a=29/42
Step-by-step explanation:
6a-1÷7=4
first write the division as a fraction
6a-1/7=4
add 1/7 to each side
6a=4+1/7
which is equal to
6a=29/7
divide both sides by 6
a=29/42
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!!
Here
360 = 24%
360=24/100
360*100=24
36000/24=1500 so ur answer is 1500
Total of 90 fish:
c + p = 90
Charlie gave 1/4 c to Peter. Now
Charlie has c - (1/4) c
Peter has p + (1/4) c
Peter gave 2/5 of his to Charlie. Now
Peter has p + (1/4) c - 2/5( p + (1/4) c )
Charlie has c - (1/4) c + 2/5( p + (1/4) c )
And then they had equal number:
c - (1/4) c + 2/5( p + (1/4) c ) = p + (1/4) c - 2/5( p + (1/4) c )
Let's do the easy subtractions then multiply by 20 to clear the fractions,
(3/4) c + 2/5( p + (1/4) c ) = 3/5( p + (1/4) c )
15c + 8p + 2c = 12p + 3c
14c = 4p
7c = 2p
c + p = 90
2c + 2p = 180
2c + 7c = 180
9c = 180
c = 20
p = 70
Answer: Charlie started with 20, Peter with 70
Check:
Initially C:20, P:70
1/4(20)=5 to P
C:15, P:75
(2/5) 75 = 30 to C
C:45, P45
Good