The perpendicular distance of the point $(-3, 8)$ from the $Y$-axis is........

If the points $A(1, 2)$,$O(0, 0)$,and $C(a, b)$ are collinear,then:

Find the coordinates of the midpoint of the segment whose end points are $A ( 4 , 3 )$ and $B ( 6 , 5 )$

If $A(4, 3)$ and $B(8, 9)$,then the midpoint of $\overline{AB}$ is $\ldots \ldots \ldots \ldots .$

In what ratio does the $x$-axis divide the line segment joining the points $(-4, -6)$ and $(-1, 7)$? Find the coordinates of the point of division.

If one vertex of a triangle is $(1, 1)$ and the midpoints of the sides through this vertex are $(-1, 2)$ and $(3, 2)$,then find the centroid of the triangle.