Three thousand hundred that is the answer
If it's just the 7 that's repeating, let
<em>x</em> = 0.1777...
Then
10<em>x</em> = 1.777...
100<em>x</em> = 17.777...
100<em>x</em> - 10<em>x</em> = 17.777... - 1.777...
90<em>x</em> = 16
<em>x</em> = 16/90 = 8/45
If both 1 and 7 are repeating, let
<em>x</em> = 0.171717...
Then
100<em>x</em> = 17.171717...
100<em>x</em> - <em>x</em> = 17.171717... - 0.171717...
99<em>x</em> = 17
<em>x</em> = 17/99
-9 duh
It says the first week look at the numbers and then the top row with numbers. the only one that matches up is -9
X to the power of 2 + 4x +5
Answer:
t = ln(0.5)/-r
Step-by-step explanation:
The decay rate parameter is missing. I will assume a value of 4% per day.
The exponential decay is modeled by the following equation:
A = A0*e^(-r*t)
where A is the mass after t time (in days), A0 is the initial mass and r is the rate (as a decimal).
At half-life A = A0/2, then:
A0/2 = A0*e^(-0.04*t)
0.5 = e^(-0.04*t)
ln(0.5) = -0.04*t
t = ln(0.5)/-0.04
t = 17.33 days
In general the half-life time is:
t = ln(0.5)/-r
