Cho hình thang ABCD có hai cạnh đáy là AB, CD và CD có độ dài gấp 3 lần độ dài AB. Hai đường chéo của hình thang là AC và BD, chúng cắt nhau tại điểm O. Biết diện tích hình tam giác OCD bằng 15 cm2, hãy tính diện tích hình thang ABCD

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.

Which table represents a linear function? i'll give brainliest to first answer ^'^

Evaluate the discriminant of each equation. tell how many solutions each equation has and whether the solutions are real or imaginary. 4x^2 + 20x + 25 = 0