Answer:
x(t) = 5000*( 1 - e^-kt)
Step-by-step explanation:
Given:
- Total number of students n = 5000
Find:
Differential equation governing the number of students x(t) who have contracted the flu.
Solution:
- Number of non-affected students = (5000 - x)
Hence,
- Rate at which students are infected:
dx / dt = k*(5000 - x )
- separate variables:
dx / (5000 - x ) = k*dt
- Integrate both sides:
- Ln(5000 - x) = kt + C
- Evaluate C for x = 0 @ t = 0
- Ln(5000 - 0) = k*0 + C
C = - Ln(5000)
- The solution to ODE is:
Ln(5000 - x) = -k*t + Ln(5000)
5000 - x = 5000*e^-kt
x(t) = 5000*( 1 - e^-kt)
Rule 1: The product<span> of a positive </span>integer<span> and a negative </span>integer<span> is a negative </span>integer<span>. Rule 2: The </span>product of two<span> negative </span>integers<span> or </span>two<span> positive </span>integers<span> is a positive </span><span>integer</span>
The answer is B. (15,18)
Solution:
First, let's set the variables first.
X = dollars per hour to clean the floor
Y = dollars per hour to clean the rest of the house
For the first statement, "<span>2 hours to clean floors and 3 hours to clean the rest of a house, the total charge is $84"
We can put it into an equation.
2X + 3Y = 84 </span>⇒ equation 1
For the first statement, "<span>1 hour to clean floors and 4 hours to clean the rest of a house, the total charge is $87'
X + 4Y = 87 </span>⇒ equation 2
Multiply first equation 2 by 2 to make the coefficient of both equations 1 and 2 the same.
Using elimination method in solving for x and y,
(equation 1) 2X + 3Y = 84
(equation 2) 2(X + 4Y) = 87
2X + 8Y = 174 ⇒ equation 3
Next, subtract equation 3 from equation 1.
2X + 3Y = 84
- (2X + 8Y = 174)
-------------------------
- 5Y = -90
Y = 18
Find X when Y = 18
@ equation 1 : 2X + 3Y = 84
2X + 3(18) = 84
2X + 54 = 84
2X = 84 - 54
2X = 30
X = 15
The answer is in ordered pairs of cleaning the floors and to clean the rest of the house. So, in the form (X,Y).
Answer: (15,18)
Answer:
.00000005708 is your answer. If it's asking you to solve the problem, 49.08
