Answer:
C. x=-3y^2
Step-by-step explanation:
The group of parabola opens left so, x=ay^2
parabola opens left so a in negative x=-3y^2
Hope it helps....
Let 
be the speed of train A, and let's set the origin in the initial position of train A. The equations of motion are
where 
are the positions of trains A and B respectively, and t is the time in hours.
The two trains meet if and only if 
, and we know that this happens after two hours, i.e. at 
Solving this equation for v we have
So, train A is travelling at 105 km/h. This implies that train B travels at
Answer:
Hello,
Step-by-step explanation:
![A=(1,2)\\B=(0,-1)\\\overrightarrow{AB}=((0,-1)-(1,2)=(-1,-3)\ ||\overrightarrow{AB}||^2=1+9=10\\\overrightarrow{BC}=((3,-2)-(0,-1)=(3,-1)\ ||\overrightarrow{BC}||^2=9+1=10\\\\Triangle\ is\ isosceles.\\\\\overrightarrow{AB}.\overrightarrow{BC}=(-1,-3)*\left[\begin{array}{c}3\\-1\end{array}\right] =-3+3=0\\\\Triangle \ is\ right.\\\\](https://tex.z-dn.net/?f=A%3D%281%2C2%29%5C%5CB%3D%280%2C-1%29%5C%5C%5Coverrightarrow%7BAB%7D%3D%28%280%2C-1%29-%281%2C2%29%3D%28-1%2C-3%29%5C%20%7C%7C%5Coverrightarrow%7BAB%7D%7C%7C%5E2%3D1%2B9%3D10%5C%5C%5Coverrightarrow%7BBC%7D%3D%28%283%2C-2%29-%280%2C-1%29%3D%283%2C-1%29%5C%20%7C%7C%5Coverrightarrow%7BBC%7D%7C%7C%5E2%3D9%2B1%3D10%5C%5C%5C%5CTriangle%5C%20is%5C%20isosceles.%5C%5C%5C%5C%5Coverrightarrow%7BAB%7D.%5Coverrightarrow%7BBC%7D%3D%28-1%2C-3%29%2A%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7D3%5C%5C-1%5Cend%7Barray%7D%5Cright%5D%20%3D-3%2B3%3D0%5C%5C%5C%5CTriangle%20%5C%20is%5C%20right.%5C%5C%5C%5C)
I found that the given prices are $ 4 per pack of pens and $ 3 per pack of penciles.
The question is how much the bookstore spent on pens.
Then you have to multiply the number packs of pens, which is 1,528, times the price per pack pens which is $ 4.
So, the answer is: 1528 packs of pens * $ 4 / pack of pens = $6112.
