The answer is A.) 3x-7y and -7y+3x
This is due to "3x" implies the value is positive, or "+3x", and -7y remains -7y.
So, we have 3x-7y and -7y+3x.
I hope this helps!
It should be a positive 5 not a negative so the error was made at the end because u divide
<h2>
Explanation:</h2>
In every rectangle, the two diagonals have the same length. If a quadrilateral's diagonals have the same length, that doesn't mean it has to be a rectangle, but if a parallelogram's diagonals have the same length, then it's definitely a rectangle.
So first of all, let's prove this is a parallelogram. The basic definition of a parallelogram is that it is a quadrilateral where both pairs of opposite sides are parallel.
So let's name the vertices as:

First pair of opposite sides:
<u>Slope:</u>

Second pair of opposite sides:
<u>Slope:</u>

So in fact this is a parallelogram. The other thing we need to prove is that the diagonals measure the same. Using distance formula:

So the diagonals measure the same, therefore this is a rectangle.
Hey! There are 7 sides and 7 vertices on a Heptagon. Hope this helps!