Tìm x, biết:
\(\frac{1}{1x2}+\frac{1}{2x3}+\frac{1}{3x4}+........+\frac{1}{Xx\left(x+1\right)}=\frac{499}{500}\)
Ai đúng cho 3tick
A= 1/1x2+ 1/2x3 + 1/3x4 +............+ 1/99x100 và 1
A=1/1x2+1/2x3+1/3x4+......+1/99x100
Tính A= 1/1x2+1/2x3+1/3x4+........+1/98x99+1/99x100
1/1x2+1/2x3+1/3x4+.....+1/9x10
1/1x2 +1/2x3 +1/3x4+…+1/99x100
Tính tổng A biết : A=1/1x2 + 1/2x3 + 1/3x4 + ... + 1/43x44 + 1/44x45
1/1x2 + 1/2x3 + 1/3x4 + ... + 1/99x100 + 1/100x101 = ...
Tìm A biết:
A=1/1x2+1/2x3+1/3x4+.....+1/18x19+1/19x20