Ta có: (x-17)/1990 + (x-21)/1986 + (x+1)/1004 = 4 => [(x-17)/1990]-1 + [(x-21)/1986]-1 + [(x+1)/1004]-2 = 0 => (x-2007)/1990 + (x-2007)/1986 + (x-2007)/1004 = 0 => (x-2007).(1/1990 + 1/1986 + 1/1004) = 0 <=> x-2007 = 0 hoặc (1/1990 + 1/1986 + 1/1004) = 0 Mà (1/1990 + 1/1986 + 1/1004) khác 0 => x-2007 = 0 x = 2007vote cho tớ nhé
Ta có:
$(x-17)/1990 + (x-21)/1986 + (x+1)/1004 = 4
$$=> [(x-17)/1990]-1 + [(x-21)/1986]-1 + [(x+1)/1004]-2 = 0
$$=> (x-2007)/1990 + (x-2007)/1986 + (x-2007)/1004 = 0
$$=> (x-2007).(1/1990 + 1/1986 + 1/1004) = 0
$$<=> x-2007 = 0 hoặc (1/1990 + 1/1986 + 1/1004) = 0
$Mà
$(1/1990 + 1/1986 + 1/1004)
$khác
$ 0
$$=> x-2007 = 0
$$x = 2007
$vote cho tớ nhé