Answer:
- <u>59.0891 g (rounded to 4 decimal places)</u>
Explanation:
<em>Half-life time</em> of a radioactive substance is the time for half of the substance to decay.
Thus, the amount of the radioactive substance that remains after a number n of half-lives is given by:
Where:
- A is the amount that remains of the substance after n half-lives have elapses, and
- A₀ is the starting amount of the substance.
In this problem, you have that the half-live for your sample (polonium-210) is 138 days and the number of days elapsed is 330 days. Thus, the number of half-lives elapsed is:
- 330 days / 138 days = 2.3913
Therefore, the amount of polonium-210 that will be left in 330 days is:
Answer:
They are both parallel lines
Step-by-step explanation:
they both have the slope of -5/4
18/25 is already simplified. There is no number that can go in both 18 and 25.
Answer:
y = 3x -8
Step-by-step explanation:
I find it convenient to start with a version of the point-slope form of the equation for a line. That is, for point (h, k) and slope m, ...
y = m(x -h) +k
For your m=3 and (h, k) = (3, 1), this equation becomes ...
y = 3(x -3) +1
Eliminating parentheses puts this in the form you desire:
y = 3x -8
To find f(-20), first figure out which piece x = -20 fits with.
Since -20 < -12, x = -20 first in the domain used by the third piece.
For f(-20), treat this function as if it was just f(x) = 3x-7.
f(-20) = 3(-20) -7
= -60 - 7
= -67
