1/3 + 1/6 + 1/10 + 1/15+.........+ 2/ X x (X+1) = 2007/2009
1/3+1/6+1/10+1/15+...+2/[x(x-1)]=2007/2009
1/3+1/6+1/10+1/15+...+2/[x(x-1)]=2007/2009
1/3+1/6+1/10+1/15+.......+2/Xx(X+1)=2007/2009
\(\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+\frac{1}{15}+...+\frac{2}{x\left(x-1\right)}=\frac{2007}{2009}\)
\(\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+\frac{1}{15}+...+\frac{2}{x\left(x-1\right)}=\frac{2007}{2009}\)
\(\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+\frac{1}{15}+.....+\frac{2}{x\left(x-1\right)}=\frac{2007}{2009}\)
tính 1/3 + 1/6 +1/10+..........+ 2/X x <x-1> + 2007/2009. hỏi X bằng bao nhiêu
BÀi 2 tìm x biết
h)2/3 x + 50% + x = 1/10
* Chú ý Dấu gạch chéo là dấu gạch ngang trong phân số nhé!
Bài 3: tìm số x biết
A) ( x+2) + ( x + 4 ) + ( x + 6) +...+ ( x + 100) = 6000
b) 1+ 2 + 3 +4 + ...+ x =15
c ) x - ( 2/ 11x13 + 20/13x15 + 20/15x17.... +20/53x55) =3/11
D) 7/4 x . ( 33/12+ 333/2020+333333/303030+33333333/42424242) = 22
e) 1/3+1/6+ 1/10+ 1/15+.....+ 2/x (x-1) = 2007/2009
g) ( 1/4+1/8+1/16+1/32+1/64+1/128+1/256). x =1
Chú ý : Dấu chấm trong câu d,g là dấu nhân nhé
