Cho hình bình hành ABCD .Gọi O là giao điểm của hai đường chéo. Kẻ AM⊥BD tại H , CN⊥BD tại K a) Chứng minh : Tứ giác AMCN là hình bình hành
b) Chứng minh : M đối xứng với N qua O
c) AM cắt DC tại H , CN cắt AB tại K . Chứng minh:Tứ giác AHCK là hình bình hành

The krasnapolski is a top-of-the-line hotel in amsterdam, the netherlands. among their many services, they rent bicycles to guests. the bicycle checkout is open 24 hours per day 7 days per week and has 50 bicycles on hand. on average, 10 guests request a bicycle each day, arriving completely randomly at all times of the day during the spring and summer seasons. guests keep bicycles for four days on average, with a standard deviation of two days. how long does a guest on average have to wait for a bike? a. approximately 24 hours b. approximately 0.033 hours c. approximately 4 days d. approximately 47 minutes

What fraction is equivalent to 0.46464646··· a. 46⁄999 b. 46⁄100 c. 46⁄99 d. 23⁄50

Jane’s favorite fruit punch consists of pear, pineapple, and plum juices in the ratio 5: 2: 3. how many cups of pear juice should she use to make 20 cups of punch?