2. Express the value of the integer x on the number axis, and click: you can find the integer solution with the number axis.

3. The absolute value, reciprocal and reciprocal of a =-2 are 2, 2,-1/2 respectively; The absolute value, reciprocal and reciprocal of b=-2/3 are 2/3, 2/3 and-3/2 respectively; The absolute value, reciprocal and reciprocal of c=5.5 are: 5.5, -5.5, 2/ 1 1 respectively.

4、0, 1

5、① 100; ②-38; ③-70; ④- 1 1; ⑤96; ⑥-9; ⑦- 1/2; ⑧75/2; ⑨-9; ⑩7.8; 1 1、5.3; 12、-289; 13、22; 14、- 16。

6、①≈245.6; ②≈ 176; ③≈ 12.00④≈6.54。

7. Victory is+,negative is-,and negative is -2.

8、79. 1。

9. First it was extended by 0.09mm, then it was shortened by 0. 1 1mm, and the final length was extended by -0.02mm compared with the original length.

10, 1.4960× 10 to the eighth power kilometer.

1 1, ① when a= 1/2, the square of a is 1/4 and the cube of a is 1/8, so a > the square of a > the cube of a (0 < a b > the cube of b (-1 < b < 0).

12, ① wrong, the inverse of 0 is 0; (2) Yes, the signs of the same even power of any two mutually opposite numbers are opposite, and their absolute values are equal; ③ No, for positive numbers and negative numbers, positive numbers are greater than negative numbers, and the reciprocal of positive numbers is still greater than the reciprocal of negative numbers.