1/2-1/3+1/4-1/5+1/6-1/7=

1/2-1/3=1/6+1/4=10/24-1/5=26/120+1/6=46/126-1/7=28/126

[tex] \frac{1}{2} - \frac{1}{3} = \frac{3 - 2}{6} = \frac{1}{6} \\ \frac{1}{4} - \frac{1}{5} = \frac{5 - 4}{20} = \frac{1}{20} \\ \frac{1}{6} - \frac{1}{7} = \frac{7 - 6}{42} = \frac{1}{42} \\ \frac{1}{6} + \frac{1}{20} + \frac{1}{42} = \frac{70 + 21 +10 }{420} = \frac{101}{420} \\ insyaallah \: benar \: ya[/tex]~insyaallah benar