a) x + ( x + 1 ) + ( x + 2 ) + ... + ( x + 2006 ) + 2007 = 2007
\(\Rightarrow\)( x + x + x + ... + x ) + ( 1 + 2 + 3 + ... + 2006 + 2007 ) = 2007
\(\Rightarrow\)2007x + 2015028 = 2007
\(\Rightarrow\)2007x = 2007 - 2015028 = -2013021
\(\Rightarrow\)x = ( -2013021 ) : 2007 = -1003
Vậy x = -1003
b) 2000 + ( 199 + x ) + ( 198 + x ) + ... + ( x + 1 ) + x = 200
\(\Rightarrow\)( x + x + x + ... + x + x ) + ( 1 + 2 + ... + 198 + 199 + 2000 ) = 200
\(\Rightarrow\)200x + 2001000 = 200
\(\Rightarrow\)200x = 200 - 2001000 = -2000800
\(\Rightarrow\)x = ( -2000800 ) : 200 = -10004
Vậy x = -10004
a, x + ( x + 1 ) + ( x + 2 ) + ..... + ( x + 2006) + 2007 = 2007
x. 2007 + ( 1 + 2 + ..... + 2006 ) = 2007 - 2007
x. 2007 + 2013021 = 0
x. 2007 = 0 - 2013021
x.2007 = - 2013021
x = ( - 2013021 ) : 2007
x = - 1003
a) x + ( x + 1 ) + ( x + 2) + ........+ ( x + 2006 ) +2007 =2007
(x+x+x+...+x)+(1+2+3+...+2007) =2007
2007.x + [(2007+1).2007 : 2] =2007
2007.x +2015028 =2007
2007.x =2007-2015028
x =(-2013021) : 2007
x = -1003
Vây x = -1003
Tìm x biết :
a)
x + ( x + 1 ) + ( x + 2) + ........+ ( x + 2006 ) +2007 =2007
b)
2000+ ( 199 +x ) + ( 198 + x ) + ( x + 1 ) + x = 200