This can be solved using a system of equations.

Subtract y from both sides.

Substitute:

Subtract 80 from both sides:

Divide both sides by 5:

Substitute.
2 meters = 200 centimeters
(-8,-5). If you think about it, for a rectangle, the x-coordinates must be the same in two pairs and the y-coordinates must be the same in two pairs. Since there are already 2 0's, 2 1's, you need a -8 and -5 to complete it. Hence, the last coordinate is (-8,-5)
To find X and Y X is horizontal Y is vertical, so that means SCP is horizontal and EF or a B is oops sorry all the way around
Not sure at all but i think the 18 one