The second question:

The third question:

The fourth question:

This part of the extended data mainly examines the knowledge points of negative numbers:

Negative numbers and positive numbers represent quantities with opposite meanings. Negative numbers are marked with a minus sign (minus sign) "-"and a positive number, for example? 2 stands for the antonym of 2.

Any positive number preceded by a negative sign becomes a negative number. A negative number is the reciprocal of its absolute value. On the number axis, negative numbers are all to the left of 0. It is stipulated in the calculation that "positive is red and negative is black", that is, red calculation means positive number and black means negative number. Comparing the sizes of two negative numbers, the absolute value is larger but smaller.

There is neither a minimum number nor a maximum number in negative numbers. The minus sign before a negative number is equal to the absolute value of the negative number. Such as -2, -5.33, -45, etc. The absolute value of 2 is 2, the absolute value of -5.33 is 5.33, the absolute value of -45 is 45, and so on. The fraction can also be a negative number, for example, the square root of the negative number of -2/5 is represented by the imaginary unit "I". (Negative numbers in real numbers have no square root)