Complete the addition-subtraction box:

(a) We have,

+ = = = 2


= 1


=


=


= 1


Therefore,


The above given number box can be completed as:






2







1







1



(b) We have,


= = =


= = =


= = =


= = =


Also,


= = = =


Therefore, the above given table can be completed as follows:




















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