Tính nhanh
a.(1+1/2)×(1+1/3)×(1+1/4)×...×(1+1/98)×(1+1/99).
b.1/2×2/3×3/4×...×97/98×98/99×99/100
1*2*3+2*3*4+3*4*5+....+97*98*99+98*99*100 = ?
1/2 +2/3 +3/4 +4/5+..+99/100
1/99+2/98 +3/97+...+98/2+99/1
help me,ai giải nhanh nhất tớ tick cho
Tính A:B
a)A=98+1/2+1/3+1/4+...+1/99
B=2/3+4/3+5/4+...+100/99
b)A=2018+1/2+1/3+1/4+...+1/2019
B=3/2+4/3+3/4+...+2020/2019
c)A=99/1+98/2+97/3+...+2/98+1/99
B=1/2+1/3+1/4+...+1/100
Giải đầy đủ
A=1/2+1/3+1/4+....+1/100
B=99/1+98/2+97/3+....+2/98+1/99
Tính: \(\frac{\frac{99}{1}+\frac{98}{2}+\frac{97}{3}+...+\frac{2}{98}+\frac{1}{99}}{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{99}+\frac{1}{100}}\)
\(\frac{1+\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{99}+\frac{1}{100}}{\frac{1}{99}+\frac{2}{98}+\frac{3}{97}+...+\frac{99}{1}+100}=?\)
tính nhanh (2/3+3/4+5/6+...+99/100).(1/2+2/3+3/4+...+98/99)-(1/2+1/3+...+99/100).(2/3+2/4+...+98/99)
100-99+98-97+............+4-3+2-1
