The value of 12×12+12(12+12)×(34) is ___.
(12)×(12)+(12)(12+12)×(34) = (12)+(14)1×(34) = (34)(34)=1
The value of (12)×(12)+(12)(12)+(12)×(34) is 1.
The value of (1)−2 + (12)−2 +(13)−2+ (14)−2 is: