It is.
<span>a parallelogram is a simple (non-self-intersecting) quadrilateral with two pairs of parallel sides. The opposite or facing sides of a parallelogram are of equal length and the opposite angles of a parallelogram are of equal measure.</span>
The answer for this question is very tricky but is to work out its B.
This is incorrect
-a = b
a + c = d
b + c = d is incorrect because it says a + c and not -a + c.
If you multiply the first line with -1 then you would get a = -b
So the final line would actually be -b+c=d
I got y=x but I’m not sure if that’s correct