The answer is B not any other mostly because you need to
subtract both equations to remove the variable.
We'll say beginning amount is 100
Ending Amount = Beginning Amount / 2^n where n is the number of half-lives
100 hours mean six and 2/3 half-lives will elapse
Ending Amount = 100/2^(6.666666)
Ending Amount = 100 /
<span>
<span>
<span>
101.59
</span></span></span>Ending Amount =
<span>
<span>
<span>
0.9843488532
</span>
</span>
</span>
So if we started with 100 grams after 100 hours (or 6.6666666 half-lives) we would only have <span>
<span>
0.9843488532
</span>
grams remaining.
http://www.1728.org/halflife.htm
</span>
I'm pretty sure its c I dont really understand stand what its asking
Since they both have 3x terms subtract the second from the first to get rid of the x terms...
3x+2y=10
-3x+y=-13
__________
3y=-3
y=-1, which makes 3x+2y=10 become: 3x-2=10 so
x=4
So the solution is the point (4, -1)