HOC24
Lớp học
Môn học
Chủ đề / Chương
Bài học
có T_T
1.The first boy who knows the truth has just moved2.I don’t remember the man whom you said you met at the canteen last week3.The only thing which make me worried is how to go home4.The most beautiful girl, whose long hair I like very much, lives in this city5.The man whom I met at the bar yesterday was Tom6.The children often go swimming on Sundays when they have much free time
lác quá
gửi lại r
Ta có: aa′+b′b=1⇔ab+a′b′a′b=1⇔ab+a′b′=a′b⇔abc+a′b′c=a′bc(1)aa′+b′b=1⇔ab+a′b′a′b=1⇔ab+a′b′=a′b⇔abc+a′b′c=a′bc(1)
Lại có: bb′+c′c=1⇔bc+b′c′b′c=1⇔bc+b′c′=b′c⇔a′bc+a′b′c′=a′b′c(2)bb′+c′c=1⇔bc+b′c′b′c=1⇔bc+b′c′=b′c⇔a′bc+a′b′c′=a′b′c(2)
Từ (1) và (2) => abc+a′b′c+a′bc+a′b′c′=a′bc+a′b′cabc+a′b′c+a′bc+a′b′c′=a′bc+a′b′c
⇔abc+a′b′c′=a′bc−a′bc+a′b′c−a′b′c⇔abc+a′b′c′=a′bc−a′bc+a′b′c−a′b′c
⇔abc+a′b′c′=0(đpcm)⇔abc+a′b′c′=0(đpcm)