Since the distance from the two known coordinates are known, you can find the slope of the line (for lack of a better word) to work backwards. there is a +5 unit gap between -21 and -16, so the next number would be -26. So, without havint to do any more work, the answer is B.
Answer:
the answer is
The point (1, −5) lie in the solution set
Area of a square:
(x-2)(x-2)
=(x-2)^2
=x^2-2x-2x+4
=x^2-4x+4 unit sq