<span>The answer to what you are looking for is 3x(3x+2)</span>
Answer:
11 persons chosen to participate in the survey
Step-by-step explanation:
A certain fraction or percentage of subjects or persons drawn randomly from a larger population is called a sample. A randomly selected set of sample will be representative of the population especially when it is impossible for the whole population to participate in the study. In the scenario above, the population or larger group would be the set of volunteers. The actual number of people chosen from the group of volunteers to participate in the survey is the sample, which are the 11 people chosen from the volunteers.
Answer:
9 hours
Step-by-step explanation:
According to Newton's laws of cooling
dT/dt = -k(T - A)
Let U = T - A
dU/dT = 1
dU = dT
dt/dt = -kU
dT = -kU(dt)
dU/U = -kdt
On integration
ln(U) = -kt + C
U = Ce^-kt
T - A = Ce^-kt
T(0) = 68
T(5) = 25
68 - 20 = Ce^-k(0)
C = 48
and
25 -20 = 48e^-k(5)
5 = 48e^-5k
e^-5k = 5/48
-5k = ln (5/48)
k = - ln(5/48) / 5
k = - 0.4524
T - 20 = 48e^-0.4524t
When T = 21
21 -20 = 48e^-0.4524t
1 = 48e^-0..4524t
e^-0.4524t = 1/48
-0.4524t = ln (1/48)
t = - ln(1/48) / 0.4524
t = 8.5570
t= 9 hours ( to the nearest hour)
Answer:
D
Step-by-step explanation:
Start by subtracting 64 from both sides:
Factor this by taking roots. Divide both sides by 25 first:
We "undo" a square by taking the square roots of both sides. Taking the square root leaves the possibilities of both the positive and negative roots of 9. Therefore, the solutions to this are
