[ x + 7/24 ] = 1/6

2/3x + 1/4 x = -22 /27

( 1975 / 1976 + 2010 / 2011 + 1963 / 1968 ) nhân ( 1 phần 3 - 1 phần 4 - 1 phần 12)

my father has watched tv for a long time 2, the boys began playing football 2 hours ago 3, he started decoroting the living room in december 4,  my sister has done her homework for 2 hours 5, we haven't gone to the cienma for ago

nam started recycling rubbish 5 years ago  viết lại câu 2, we have donated books and clothes for 5 years 3, the students haven't cleaned up the streets for 2 weeks 4, when did your mother donate blood 5, I have never read this novel before