Tính A
A= 4/3 + 16/15 + 36/35 + ..... +9604/9603
Tính A
A= 4/3 + 16/15 + 36/35 + ..... +9604/9603
Tính A
A= 4/3 + 16/15 + 36/35 + ..... +9604/9603
Tính A
A= 4/3 + 16/15 + 36/35 +.....+ 9604/9603
Tính A
A= 4/3 + 16/15 + 36/35 + .......... + 9604/9603
Tính A
A= 4/3 + 16/15 + 36/35 + .......... + 9604/9603
Tính A
A= 4/3 + 16/15 + 36/35 + .......... + 9604/9603
\(A=1+\frac{1}{3}+1+\frac{1}{15}+...+1+\frac{1}{9603}\)
\(A=1+\frac{1}{1\cdot3}+1+\frac{1}{3\cdot5}+...+1+\frac{1}{97\cdot99}\)
\(A=49+\frac{1}{1\cdot3}+\frac{1}{3\cdot5}+...+\frac{1}{97\cdot99}\)
\(A=49+\frac{1}{2}\left(\frac{2}{1\cdot3}+\frac{2}{3\cdot5}+...+\frac{2}{97\cdot99}\right)\)
\(A=49+\frac{1}{2}\left(1-\frac{1}{3}+\frac{1}{3}-\frac{1}{5}+...+\frac{1}{97}-\frac{1}{99}\right)\)
\(A=49+\frac{1}{2}\left(1-\frac{1}{99}\right)=49+\frac{49}{99}=\frac{4900}{4851}\)
tinh nhanh
4/3-8/15+12/35-16/63+....+188/8832-192/9215+196/9603
Tính
A=4/1.3 + 16/3.5 + 36/5.7 + ..... + 9604/97.99