Answer:41.36
Step-by-step explanation:
Answer:
Step-by-step explanation:
Given the differential equation
25y′′+40y′+16y=0
Using D operator to find the complementary solution
Since the Differential equation is equal to 0, then it doesn't have a partial solution.
25y′′+40y′+16y=0
25D² + 40D +16 = 0
25D² + 20D + 20D +16 = 0
5D(5D+4)+4(5D+4)= 0
(5D+4)=0 twice
D = -4/5 twice,
So the solution is a real and equal roots
y(t) = (A+B•t) exp(—0.8t)
Where A and B are constant
The initial value are.
y(0)=a, y′(0)=−1
y(0) = a = (A+B(0)) exp(—0.8(0))
a = A
Then, the constant A = a.
Now, y'(t)
y'(t)=B•exp(-0.8t)-0.8(A+B•t)exp(-0.8t
-1 = B - 0.8A
Since A =a
Then, B = 0.8a —1
The solution becomes
y(t) = (a+(0.8a-1)•t) exp(—0.8t)
For t>0
For positive,
a + (0.8a -1)> 0
1.8a > 1
a > 1/1.8
a > 10/18 > 5/9
a > 5/9.
Answer:
7x - 35 + 12 - 2x = 12
Step-by-step explanation:
Distribution is the first step. Multiply 7 to x and -35. And multiply 2 to 6 and -x. That gives you the answer 7x - 35 + 12 - 2x = 12.
Answer: (1,4)
Explanation: The domain looks at the x coordinates and (1,4) is the only x coordinate in the range given (due to the bracket)
Horse = x = 1 head and 4 feet
Chicken =y = 1 head and 2 feet
Horse + chicken = x + y = 43 ( total heads)
Horse = 43 - y
4x + 2y = 122
4(43-y) + 2y = 122
Simplify:
172-4y + 2y = 122
Combine like terms
172-2y = 122
Subtract 172 from both sides
-2y = -50
Divide both sides by-2
Y = 25
X + y = 43
X + 25 = 43
X = 18
There are 18 horses and 25 chickens.
