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20 16 national junior high school mathematics joint competition questions ninth grade answer urgent! ! ! !
1, line y = x+2 (- 1

Line segment y = x+2 (- 1

Choose B.

2. The combination of dice with | a-b | = 2 is (1, 3) (3,1) (2,4) (4,2) (3,5) (5,3) (4,6) (6,4).

The total number of possible combinations for rolling the dice twice is 6*6=36, so the probability of |a-b|=2 is 8/36=2/9.

Choose B.

Please adopt