\(\frac{1}{2}+\frac{1}{6}+\frac{1}{12}+........+\frac{1}{56}\)
\(=\frac{1}{1.2}+\frac{1}{2.3}+...........+\frac{1}{7.8}\)
\(=1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+......+\frac{1}{7}-\frac{1}{8}\)
\(=1-\frac{1}{8}=\frac{7}{8}\)
2*x+1/2*x + 6*x+1/6*x +12*x+1/12*x +20*x+1/20*x= 5.tìm x
2*x+1/2*x+6*x+1/6*x+12*x+1/12*x+20*x+1/20*x=5.Tim x
tinh bang cach thuan tien nhat
1/2+1/6+1/12+1/20
1/2+1/6+1/12+1/20+..........+1/9900
1/2+1/3+1/4+1/8+1/16
1/2+1/3+1/4+1/8+1/16+........+1/512
{1+1/2+1/6}:{1/6+1/12+1/20}
các bạn giải hộ mh bài này nhé
b1,
a,1/2 + 1/6 + 1/12 + 1/20 +...+ 1/9500
b, 3/2 - 5/6 - 7/12 - 9/20 - ....- 19/90
1/2 + 1/6 + 1/12 + 1/20 + 1/30
1\2 + 1\4 + 1\6 + ... + 1\156 + 1\512 = ?
( 1/2 + 1/6 + 1/12 + 1/20+......+1/72) : X = 1/2+ 1/4
( 1/2 + 1/6 + 1/12 + 1/20 ) × ( 20 - x ) = 4
Tìm x
