The coordinates of parallelogram ABCD are A(0, 0), B(a, 0), C( , ), and D(c, b). The coordinates of the midpoint of AC¯¯¯¯¯ are ( ,b2). The coordinates of the midpoint of BD¯¯¯¯¯ are (a+c2, ). The midpoints of the diagonals have the same coordinates. Therefore, AC¯¯¯¯¯ and BD¯¯¯¯¯ bisect each other.

Plzzz plzz maths ! quadratic sequences =an^2+bn 1) 1,6,15,28,45 2)5,18,39,68,105 3) 1,8,21,40,65 4) 7,24,51,88,135 5) -1,2,9,20,35

At the olympic games, many events have several rounds of competition. one of these events is the men's 100-meter backstroke. the upper dot plot shows the times (in seconds) of the top 8 finishers in the final round of the 2012 olympics. the lower dot plot shows the times of the same 8 swimmers, but in the semifinal round. which pieces of information can be gathered from these dot plots? (remember that lower swim times are faster.) choose all answers that apply: a: the swimmers had faster times on average in the final round. b: the times in the final round vary noticeably more than the times in the semifinal round. c: none of the above.

Two cyclists 84 miles apart start riding toward each other at the samen time. one cycles 2 times as fast as the other. if they meet 4 hours later what is the speed (in miles) of the faster cyclists