key
1. List the denominators respectively; The key to general division is to determine the simplest common denominator of several fractions, and the steps are as follows:
2. Multiply the divisor of the denominator. If there is a common divisor, the result is the least common multiple of the denominator;
3. All the letters or factors based on letters should be taken;
4. The factor with the same letter or the power of the factor with the letter takes the largest exponent;
5. Multiply all the above formulas to get the simplest common denominator;
step
1. Find the simplest common denominator of the denominator of the original fraction (formula) first;
2. According to the basic properties of the fraction (formula), the original fraction (formula) is changed to a fraction (formula) with the simplest common denominator as the denominator.
according to
The basis of general score and approximate score is the basic property (formula) of score:
The numerator and denominator of a fraction (formula) are multiplied or divided by a number (formula) that is not equal to zero, and the size of the fraction (formula) remains unchanged. The denominator remains the same, and the denominator on the other side is cross-multiplied.
example
① Total scores: 1/3 and 1/4.
Solution: The least common multiple of 3 and 4 is 12.
1/3 = 4/ 12
1/4 = 3/ 12
Then the scores are 4/ 12 and 3/ 12.
② Compare the sizes of 7/9 and 8/ 1 1.
Solution: 7/9 = 7×11/9×1= 77/99.
8/ 1 1 = 8×9 / 1 1×9 = 72/99
∫77/99 >72/99
∴7/9 & gt； 8/ 1 1