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.