\(\frac{1}{1x3}+\frac{1}{3x5}+....+\frac{1}{97x99}\)=S
\(2S=\frac{3-1}{1x3}+\frac{5-3}{3x5}+...+\frac{99-97}{97x99}\)
\(2S=1-\frac{1}{3}+\frac{1}{3}-\frac{1}{5}+....+\frac{1}{97}-\frac{1}{99}=1-\frac{1}{99}=\frac{98}{99}\)
\(S=\frac{2S}{2}=\frac{49}{99}\)
1/1x3 + 1/3x5 + 1/5x7 + .... + 1/97x99
A = \(\frac{1}{1x3}\)+ \(\frac{1}{3x5}\)+ \(\frac{1}{5x7}\)+ ..... + \(\frac{1}{97x99}\)
tính bằng cách hợp lí
3/1x3 + 3/3x5 + 3/5x7 +.....+3/97x99
A =\(\frac{1}{1x3}\) +\(\frac{1}{3x5}\) + \(\frac{1}{5x7}\) + ..... +\(\frac{1}{97x99}\)
6/1x3 + 6/3x5 + 6/5x7 + ...+6/ 97x99
Mình cần gấp
ai giúp mình mình sẽ tick
tinh gia tri bieu thuc:
a) M = \(\frac{1}{1x2}+\frac{1}{2x3}+\frac{1}{3x4}+....+\frac{1}{99x100}\)
b)N = \(\frac{1}{1x3}+\frac{1}{3x5}+\frac{1}{5x7}+...+\frac{1}{97x99}\)
\(x\)la dau nhan
gâp ạ
Tính nhanh giá trị biểu thức sau:
\(\frac{2}{1x3}+\frac{2}{3x5}+\frac{2}{5x7}+.....+\frac{2}{95x97}+\frac{2}{97x99}\)
1/3x1 + 1/3x5 + ......+ 1/95x97 + 1/97x99
a)1/1x3+1/3x5+1/5x7+...+1/Xx(x+3)=99/200
b)1/1x3+1/3x5+1/5x7+...+1/Xx(x+2)
