Given: y is the midpoint of xz
prove: xy = 1/2xz

Find an bif a = {3, 6, 9, 12) and b = {2, 4, 6, 8, 10).

Set $r$ is a set of rectangles such that (1) only the grid points shown here are used as vertices, (2) all sides are vertical or horizontal and (3) no two rectangles in the set are congruent. if $r$ contains the maximum possible number of rectangles given these conditions, what fraction of the rectangles in set $r$ are squares? express your answer as a common fraction.

Write the equations in logarithmic form 9^4=6,561