What is the distance of the point (−9, 40) from the origin?

The distance from the origin is √$(x^2+y^2)$ = √$((-9{)}^2+40^2)$ = √(81 + 1600) = √1681 = 41 units. The negative sign disappears when the coordinate is squared, so subtracting or adding the coordinates (31 or 49) is not valid, and 1681 is the square of the distance rather than the distance itself.