Answer:
x^2 + 2xy + y ^2
Step-by-step explanation:
A = a^2
a = x + y
(x + y) + (x + y)
x^2 + xy + xy + y^2
x^2 + 2xy + y ^2
Answer:
The measure of an arc refers to the arc length divided by the radius of the circle. The arc measure equals the corresponding central angle measure, in radians. That's why radians are natural: a central angle of one radian will span an arc exactly one radius long.
Answer:
3:36 PM
Step-by-step explanation:
Let fraction (y) of the people that heard the rumor , the differential equation that is satisfied by the by y is,

Solving the differential equation,
![y(t) = \frac{y_{o}}{[y_{o} + (1 + y_{o})e^{-kt}]}](https://tex.z-dn.net/?f=y%28t%29%20%3D%20%5Cfrac%7By_%7Bo%7D%7D%7B%5By_%7Bo%7D%20%2B%20%281%20%2B%20y_%7Bo%7D%29e%5E%7B-kt%7D%5D%7D)
The total number of inhabitants of the town = 2000
The number of people that heard the rumor = 160
At 8 AM, let t = 0,

= 0.08
By noon, half of the town as heard the rumor.
Then,

Therefore,
![\frac{1}{2} = \frac{0.08}{[0.08 + (1 - 0.08)e^{-4k}]}](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B2%7D%20%3D%20%5Cfrac%7B0.08%7D%7B%5B0.08%20%2B%20%281%20-%200.08%29e%5E%7B-4k%7D%5D%7D)
![\frac{0.08}{[0.08 + 0.92e^{-4k}]} = \frac{1}{2}](https://tex.z-dn.net/?f=%5Cfrac%7B0.08%7D%7B%5B0.08%20%2B%200.92e%5E%7B-4k%7D%5D%7D%20%3D%20%5Cfrac%7B1%7D%7B2%7D)




k ≈ 0.06106
Calculating time, t when y(t) = 90%
⇒ y(t) = 0.9
![\frac{0.08}{[0.08 + 0.92e^{-0.06106t}]} =0.9](https://tex.z-dn.net/?f=%5Cfrac%7B0.08%7D%7B%5B0.08%20%2B%200.92e%5E%7B-0.06106t%7D%5D%7D%20%3D0.9)





t = 7.59 hours
⇒ 7 hours 36 minutes
From 8 A.M. plus 7 hours 36 minutes = 3:36 PM
At 3:36 PM will 90% of the population have heard the rumor
Cost of a hat bought by Marcel = 
Cost of a pair of socks = 
Cost of 2 pair of socks =
= 
Total price of hat and two pair of socks = 
A sales tax of
on this purchase = 
=
=
2.25
Therefore, the total price including the sales tax = 
=