chưng tỏ 1/1.2.3 +1/2.3.4 + 1/3.4.5+...+1/98.99.100=4949/19800
chứng tỏ
1/1.2.3 + 1/2.3.4 + 1/3.4.5 + ... + 1/98.99.100 = 4949/19800
chứng tỏ : \(\frac{1}{1.2.3}\)+\(\frac{1}{2.3.4}\)+\(\frac{1}{3.4.5}\)+.........+\(\frac{1}{98.99.100}\)= \(\frac{4949}{19800}\)
giải gấp mk nha! nếu đúng mh tick cho.
Tính nhanh
A=6+16+30+48+...+19600+19998
B=2+5+9+14+...+4949+5049
C=1.2.3+2.3.4+3.4.5+...+98.99.100
CMR:
\(\frac{1}{1.2.3}+\frac{1}{2.3.\text{4}}+\frac{1}{3.\text{4}.5}+...+\frac{1}{98.99.100}=\frac{\text{4}9\text{4}9}{19800}\)
Tính:
1/1.2.3 +1/2.3.4+.....+1/98.99.100
\(B=\frac{1}{1.2.3}+\frac{1}{2.3.4}+.........+\frac{1}{98.99.100}\)
tính:A=\(\frac{1}{1.2.3}+\frac{1}{2.3.4}+\frac{1}{3.4.5}+...+\frac{1}{98.99.100}\)
Tính tổng:
a,S=1.4+4.7+7.10+...+301.304
b,S=1/1.2.3+1/2.3.4+....+1/98.99.100
