Answer:
(-3,-20)
Step-by-step explanation:
4 +8x = y ...... equation (1)
6x - y = 2 ........equation(2)
from equation 2
6x - y = 2
6x -(4+8x) =2
6x - 4 + 8x = 2
+4 +4
6x - 8x = 6
-2x=6
divide by -2
x= -3
put x in equation (1) to solve for y
4 + 8x = y
4+8(-3)=y
4-24=y
-20=y
y= -20
solution = (-3,-20)
For this case we have the following data:


So that the figure can be a rectangle, its diagonals must be equal, that is, 
In this way we have:

Clearing x we have:


Thus, x must be equal to 10 so that the figure is a rectangle.
Answer:

Option A