O resultado x² – 4a² é obtido por meio de qual dos produtos notáveis abaixo? (yx - 2a)²
(yx + 2a)(yx + 2a)
(x + 2a)(x – 2a)
(x + a)(x + 2)
(yx + 2a)²

Which statement about perfect cubes is true

Abag contains 4 red, 7 blue and 5 yellow marbles. event a is defined as drawing a yellow marble on the first draw and event b is defined as drawing a blue marble on the second draw. if two marbles are drawn from the bag, one after the other and not replaced, what is p(b|a) expressed in simplest form? a. 7/16 b. 7/15 c. 14/16 d. 14/15

How can you tell when x and y are not directly proportional?