1, the same number is added (subtracted) on both sides of the equation, and the sign of the equation remains unchanged;

2. Both sides of the equation are multiplied (divided) by the same number that is not 0, and the sign of the equation remains unchanged;

The basic properties of the score:

1, the denominator of the fraction is multiplied (divided) by the same number that is not 0, and the value of the fraction remains unchanged;

Fractional addition and subtraction properties:

1, add and subtract fractions with the same denominator, denominator unchanged, numerator addition and subtraction;

2. Add and subtract fractions with different denominators, and then add and subtract fractions with the same denominator.