the answer for this would be the last one. two rays that meet at a end point.
hope this helps!
Answer:
add the whole numbers. -9+10=1
1 2-3/7
remove one digit from the whole number:. 1-1=0
add the denominator to 2=7+2=9
:. 9-3/7=6/7
answer=6/7
Answer:
Ok, an exponential decay is written as:
P(t) = A*(1 - r)^t
Where A is the initial population, r is the rate of decay and t is the unit of time.
We know that the initial population is 15g
then:
P(t) = 15g*(1 - r)^t
And at t = 3hs, the populations is 5g
P(5h) = 5g = 15g*(1 - r)^5
5/15 = 1/3 = (1 - r)^5
(1/3)^(1/5) = (1 - r) = 0.8
Now, the half life time of the sustance is t = x, such that the population reduces to it's half:
P(x) = A/2 = 15g/2 = 7.5g
Then:
7.5g = 15g*0.8^x
7.5g/15g = 1/2 = 0.8^x
Now, remember that if we have:
a = b^x
then
x = ln(a)/ln(b)
ln(1/2)/ln(0.8) = x = 3,11 hours
