The "k" value should have units and should be negative.
k = -.07 / seconds
Half-Life = ln (.5) / k
Half-Life = ln (.5) / -.07
Half-Life = -.693147 / -.07
Half-Life = 9.9 seconds
(actually, wkpedia says half-life of Krypton 91 is 8.57 seconds)
elapsed time = half-life * log (bgng amt / end amt) / log (2)
elapsed time = 9.9 * log (100 / 10) / 0.30102999566
elapsed time = 9.9 * 1 / 0.30102999566
<span><span>elapsed time = 9.9 * 3.3219280949
</span>
</span><span><span><span>elapsed time = 32.8870881395
</span>
</span>
</span>
<span>elapsed time = 32.89 seconds (rounded)
Source:
http://www.1728.org/halflife.htm
</span>
Answer:
Let's solve your equation step-by-step.
p=(0.5)(2.718282)−5
Step 1: Simplify both sides of the equation.
p=(0.5)(2.718282)−5
p=1.359141+−5
p=(1.359141+−5)(Combine Like Terms)
p=−3.640859
p=−3.640859
Answer:
p=−3.640859
Step-by-step explanation:
Answer:
13 pencils.
Step-by-step explanation:
Let x be the pens and y be the pencils
Given:
Brian purchased pens for 75 cents each and pencils for 40 cents each he bought total of 22 writing utensils for $11.95.
Total pens and pencils is 22
So,
----------------(1)
And he bought all utensils for $11.95. and each pen for 75 cents and pencils for 40 cents.
------------(2)
solve equation 1 and equation 2 for x and y.
From equation 1.

----------------(3)
put y value in equation 2.







Now substitute x value in equation 3.


So, he buy 13 pencils.
9x^2+t+25=(ax+b)^2
9x^2+t+25=a^2*x^2+2abx+b^2 so
a^2=9 so a=3
b^2=25 so b=5 then
t=2ab using a and b from above
t=2*3*5=30
So the missing term is 30x