Answer:
Coordinates switch, and the new y-coordinate changes sign
Explanation:
We have point A with the coordinates (-1,2), when we rotate it c90º it becomes (2,1).
What happened? The coordinates switched and the x-coordinate of A (-1) became the y-coordinate of A' (1) and it changed its sign.
if the diameter is 15, its radius is half that, or 7.5
![\bf \textit{area of a circle}\\\\A=\pi r^2~~\begin{cases}r=radius\\[-0.5em]\hrulefill\\r=7.5\end{cases}\implies A=\pi 7.5^2\implies A=56.25\pi \\\\\\A\approx 176.71459\implies A = \stackrel{\textit{rounded up}}{177}](https://tex.z-dn.net/?f=%5Cbf%20%5Ctextit%7Barea%20of%20a%20circle%7D%5C%5C%5C%5CA%3D%5Cpi%20r%5E2~~%5Cbegin%7Bcases%7Dr%3Dradius%5C%5C%5B-0.5em%5D%5Chrulefill%5C%5Cr%3D7.5%5Cend%7Bcases%7D%5Cimplies%20A%3D%5Cpi%207.5%5E2%5Cimplies%20A%3D56.25%5Cpi%20%5C%5C%5C%5C%5C%5CA%5Capprox%20176.71459%5Cimplies%20A%20%3D%20%5Cstackrel%7B%5Ctextit%7Brounded%20up%7D%7D%7B177%7D)
Let, the speed of boat = x
Speed of current = y
So, x + y = 280/7
x + y = 40 ---- first equation
x - y = 280/14
x - y = 20
x = 20 + y
Substitute this value of x in first equation,
20 + y + y = 40
2y = 40 - 20
y = 20/2
y = 10
Substitute this in first equation,
x + 10 = 40
x = 30
In short, Speed of Boat = 30 mph, & speed of current = 10 mph
Hope this helps!
Answer:
D
Step-by-step explanation:
0=3x-7
0=3x+7
7=3x/3
7/3=x
<span>The cost of producing a new watch is $50. At a price of $100, watches will most likely be sold and good.</span>