Sometimes, instead of errors, bits are erased during the transmission of a message or from a tape or other storage medium. The position, but not the value, of an erased bit is known. We say that a code C can correct r erasures if a message received with no errors and with no more than r erasures can be corrected to a unique codeword that agrees with the message received in all the positions that were not erased. a) Show that a binary code of minimum distance d can correct d − 1 erasures. b) Show that a binary code of minimum distance d can correct t errors and r erasures if d = 2t + r + 1.

The avenues in a particular city run north to south and are numbered consecutively with 1st avenue at the western border of the city. the streets in the city run east to west and are numbered consecutively with 1st street at the southern border of the city. for a festival, the city is not allowing cars to park in a rectangular region bordered by 5th avenue to the west. 9th avenue to the east, 4th street to the south, and 6th street to the north. if x is the avenue number and yis the street number, which of the following systems describes the region in which cars are not allowed to park? 5th ave 9th ave

Graph y = -|x| + 2. click on the graph until the correct one appears.

Acoffee shop orders at most $3,500 worth of coffee and tea. the shop needs to make a profit of at least $1,900 on the order. the possible combinations of coffee and tea for this order are given by this system of inequalities, where c = pounds of coffee and t = pounds of tea: 6c + 13t ≤ 3,500 3.50c + 4t ≥ 1,900 which graph's shaded region represents the possible combinations of coffee and tea for this order?