Vì \(\frac{1}{32}+\frac{1}{33}+.....+\frac{1}{89}+\frac{1}{90}>0\)
Mà\(1>\frac{2}{3}\)
=>\(1+\frac{1}{31}+\frac{1}{32}+.....+\frac{1}{90}>0+\frac{2}{3}\)
=>\(1+\frac{1}{31}+\frac{1}{32}+....+\frac{1}{90}>\frac{2}{3}\)
Vậy......
bn ơi trên bàn phím mt có dấu \(+\) mak!
1 + \(\frac{1}{31}\)+ \(\frac{1}{32}\) > \(\frac{1}{90}\)+ \(\frac{2}{3}\)
Nhớ tk mình nha !