👤

1/7•8+1/8•9+1/9•10+1/10•11
Vă rog dau coroană plus follow!​


Răspuns :

1/7*8=1/7 - 1/8

1/8*9=1/8 - 1/9

1/9*10=1/9 - 1/10

1/10*11= 1/10 - 1/11

1/7-1/8+1/8-1/9+1/9-1/10+1/10-1/11=1/7 - 1/11= 11/77 - 7/77= 4/77