Xét vế phải: \(\frac{1}{q+1}+\frac{1}{q\left(q+1\right)}\)=\(\frac{q}{q\left(q+1\right)}+\frac{1}{q\left(q+1\right)}\)
=\(\frac{q+1}{q\left(q+1\right)}\)
=\(\frac{1}{q}\)= Vế trái
=> \(\frac{1}{q}=\frac{1}{q+1}+\frac{1}{q\left(q+1\right)}\)(Đpcm)
cmr
a,1/q=1/q+1+1/q(q+1) (q khác 0;q khác 1)
CMR : a/b = 1/q+1 + a(q+1)-b/b(q+1)
CMR: a/b = 1/1+9 +a*(q+1)-b /b*(q+1)
(a,b,q thuộc Z, b khác 0; q khác -1)
CHO A=1+\(\frac{1}{2}\)+\(\frac{1}{3}\)+\(\frac{1}{4}\)+...........+\(\frac{1}{100}\)
CMR A KO LA STN
CHO A=\(\frac{1}{2^2}\)+\(\frac{1}{3^2}\)+\(\frac{1}{4^2}\)+.......+\(\frac{1}{2016^2}\)
CMR A KO PHẢI LÀ STN
AI LÀM ĐC MK TICK CHO
CMR : 1+\(\frac{1}{2}\)+\(\frac{1}{3}\)+\(\frac{1}{4}\)+....+\(\frac{1}{255}\)+\(\frac{1}{256}\)> 5
CMR \(\frac{1}{1\cdot2}\)+ \(\frac{1}{2\cdot3}\)+ ...+\(\frac{1}{49\cdot50}\)= \(\frac{1}{26}\)+\(\frac{1}{27}\)+\(\frac{1}{28}\)+....+ \(\frac{1}{50}\)
CMR: A=1+ \(\frac{1}{1!}\)+ \(\frac{1}{2!}\)+ \(\frac{1}{3!}\)+......+\(\frac{1}{2019!}\)< 3
CMR : \(\frac{1}{5}\)+ \(\frac{1}{6}\)+\(\frac{1}{7}\)+\(\frac{1}{8}\)+ .... + \(\frac{1}{17}\) < 2
CMR:
\(\frac{1}{41}\)+ \(\frac{1}{42}\)+\(\frac{1}{43}\)+...+\(\frac{1}{79}\)+\(\frac{1}{80}\)>\(\frac{7}{12}\)
