Which expression would be easier to simplify if you used the associative property to change the grouping? A. 85 + (120 + 80)

B. [-40 + (60)] + 52

C. (2 + 3/7) + 4/7

D. 4 + (1.2 + (-0.2))

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.

The measurement of one angle of a right triangle is 42° what is the measurement of the third angle? (there is no picture)

What are linear equations? could'ya explain too me, ? ! and how do you see what graph is a proportional relationship?