What does m∠1 ≅ m∠5 mean?

If f(x) = 4x – 3 and g(x) = 8x + 2, find each function value a. f[g(3)] b. g[f(5)] c. g{f[g(-4)]}

Yesterday, george drank 1 small bottle and 2 large bottles, for a total of 1,372 grams. the day before , he drank 1 small bottle and 1 large bottle, for the total of 858 grams. how many grams does each bottle hold?

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.