Answer:
A. (x + 2)^2 = 31.
Step-by-step explanation:
x^2 + 4x = 27
x^2 + 4x - 27 = 0
A. (x + 2)^2 = 31
x^2 + 4x + 4 - 31 = 0
x^2 + 4x - 27 = 0
This option corresponds to the given equation, so it is correct.
B. (x + 2)^2 = 43
x^2 + 4x + 4 - 43 = 0
x^2 + 4x - 39 = 0
This does not correspond to the equation.
C. (x + 4)^2 = 31
x^2 + 8x + 16 - 31 = 0
x^2 + 8x - 15 = 0
This does not correspond to the equation.
D. (x+4)^2 = 43
x^2 + 8x + 16 - 43 = 0
x^2 + 8x - 27 = 0
This does not correspond to the equation.
So, your answer is A. (x + 2)^2 = 31.
Make sure to SUBMIT and check your PREVIOUS answers to make sure they are right! XD Also, hope this helps!
Answer:
Step-by-step explanation:
Let's use the definition of the Laplace transform and the identity given:![\mathcal{L}[t \cos 5t]=(-1)F'(s)](https://tex.z-dn.net/?f=%5Cmathcal%7BL%7D%5Bt%20%5Ccos%205t%5D%3D%28-1%29F%27%28s%29)
with ![F(s)=\mathcal{L}[\cos 5t]](https://tex.z-dn.net/?f=F%28s%29%3D%5Cmathcal%7BL%7D%5B%5Ccos%205t%5D)
.
Now, 
. Using integration by parts with u=e^(-st) and dv=cos(5t), we obtain that 
.
Using integration by parts again with u=e^(-st) and dv=sin(5t), we obtain that
.
Solving for F(s) on the last equation, 
, then the Laplace transform we were searching is 
Step-by-step explanation:
2⁵ˣ = 8ˣ⁺²
2⁵ˣ = (2³)ˣ⁺²
2⁵ˣ = 2³ˣ⁺⁶
5x = 3x + 6
2x = 6
x = 3
Answer:
4/69 to be exact. Slightly greater than 1/18
Step-by-step explanation:
The chance of selecting the PB cookie on the first try is 4 out of 24 or 1 out of 6. There are now 23 coolies left; 8 are chocolate, so 8/23 chance. (Slightly greater than 1/3) The chance of both events happening is the product if the individual events' chances. So multiply 1/6 times 8/23 to get 8/138. That reduces to 4/ 69. If he had put that first cookie back, the multiplication would have been 1/6×1/3. A lot easier.
