tim x ; 1/x(x+1)+1/(x+1)(x+2)+1/(x+2)(x+3)-1/x=1/2010
tim x ; 1/x(x+1)+1/(x+1)(x+2)+1/(x+2)(x+3)-1/x=1/2010
Tim so tu nhien x biet:
a,x+(x+1)+(x+2)+...+(x+2010)=2029099
b,2+4+6+8+...+2x=210
Tìm x, y ∈ N biết: (1-1/1+2).(1-1/1+2+3).(1-1/1+2+3+4). .... .(1-1/1+2+...+x) = 672/2010
tìm x biết ( 1/2 + 1/3 + ... + 1/2012 + 1/2013 ) .x = 2012/1 + 2011/2 + 2010/3 + ... + 2/2011 + 1/2012
Tim x
a,-2/3(x-1/4)=1/3(2x-1)
b,1/5.2^x +1/3.2^x+1=1/5.2^7 +1/3.2^8
Bai 1.Tim x:
x-{x-[x-(-x+1)]}=1
Bai 2. Tinh:
1+(-2)+3+(-4)+..............+2015
giup minh voi!!!
tim x biet:
( 1/2 +1/3+ 1/4+ 1/5+ 1/6 +1/7)x (2009 * x ) = 0.63* 0.12 - 2,1 * 0,036
tim x biet -2/3 (x-1/4)=1/3( 2x -1)
tìm x biết x+1/2011+x+2/2010+x+3/2009+x+4/2008 =-4
tim tich: A= (1+1/1 x 3)x(1+1/2x4)x(1+1/3x5)x............x(1+1/2011x2013)