I'm may not be that good at math, but I'm going to try my best to help you, because I know how it feels to be in this situation!
The first one :
You might be right on D. But I'm thinking B also. The question asks "Which could be a cross section of a rectangular pyramid that has been intersected by a plane perpendicular". But a triangle is basically a flat pyramid.
(I'm typing really fast to help!!!!)
Second one: Its B!! Look at it really closely! You'll get it!!!
(Going really fast now!!!!)
Third one: Between B or D!!! But I think you're right on your choice!!!!
(FASTER FASTER!!!)
FINALLY: Copy and paste your answers into google. People have asked the same question!
I hope I helped. I don't want to make you fail, as I am in the SAME similar situation as you! I really REALLY REALLY HOPE YOU PASS!!!
So, I'm going to break it down to help you understand it a bit more.
If it starts at (0,-2) and crosses through (1,0) that means it moved to the right once and up twice. Which means, that the slope will be 2. If it were one it would be to the right 1 up one, if it were 4 it would be to the right 1 up 4, and finally if it were 1/2 it would be to the right 2 up 1.
So, your answer is C. or 2.
- Midpoint Formula:

So firstly, let's start with the x-coordinates. Since we know the midpoint's x-coordinate and point A's x-coordinate, we can solve for point B's x-coordinate as such:

Next, do the same thing except solve for the y-coordinate and using point A's y-coordinate and the midpoint's y-coordinate:

<u>Putting it together, point B's coordinates are (2,4).</u>
Multiply 2.90 by 6 and multiply 2.90 by 4 then add them and you get your answer