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What number should be added to both sides of the equation to complete this square? x^2-10x=7

Question part points submissions used suppose that 100 lottery tickets are given out in sequence to the first 100 guests to arrive at a party. of these 100 tickets, only 12 are winning tickets. the generalized pigeonhole principle guarantees that there must be a streak of at least l losing tickets in a row. find l.

Which of the following statement about pascal's triangle are true?