Question

8/11-4/15=?27/50-9/20=?432/500-111/300=?19/20-3/25=?помогите, пожалуйста , с решением. и если можно, объясните. ведь нужно приводить к общему знаменателю, не понимаю, как

Answer 1

Смотри,надо найти такое число,которое будет делиться и на первый знаменатель и на 2)
1) 8/11-4/15=ищем число,которое делится и на 11 и на 15,например 156,далее делим поочередно это число на каждый знаменатель,156\11,получается 15,это будет дополнительный множитель к 1 дроби,так же 156/15,будет 11,это дополнительный множитель ко 2 дроби. теперь 8 умножаем на первый дополнительный множитель,а 4 на второй,будет 120-44/156,досчитываем и получается 76/156,можно сократить на 4,будет 19/39
2)9/100
3)714/1500=119/250
4)68/100=17/25

Answer 2

Calculating Subtractions Involving Fractions

To solve the given subtraction problems involving fractions, we need to find a common denominator for each pair of fractions and then perform the subtraction. Let's go through each calculation step by step.

1. 8/11 - 4/15: To subtract 4/15 from 8/11, we need to find a common denominator. The least common multiple (LCM) of 11 and 15 is 165. We can then convert both fractions to have a denominator of 165 and perform the subtraction.

The calculation is as follows: ``` 8/11 - 4/15 = (8*15)/(11*15) - (4*11)/(15*11) = 120/165 - 44/165 = 76/165 ```

Therefore, 8/11 - 4/15 = 76/165.

2. 27/50 - 9/20: To subtract 9/20 from 27/50, we need to find a common denominator. The LCM of 50 and 20 is 100. We can then convert both fractions to have a denominator of 100 and perform the subtraction.

The calculation is as follows: ``` 27/50 - 9/20 = (27*2)/(50*2) - (9*5)/(20*5) = 54/100 - 45/100 = 9/100 ```

Therefore, 27/50 - 9/20 = 9/100.

3. 432/500 - 111/300: To subtract 111/300 from 432/500, we need to find a common denominator. The LCM of 500 and 300 is 1500. We can then convert both fractions to have a denominator of 1500 and perform the subtraction.

The calculation is as follows: ``` 432/500 - 111/300 = (432*3)/(500*3) - (111*5)/(300*5) = 1296/1500 - 555/1500 = 741/1500 ```

Therefore, 432/500 - 111/300 = 741/1500.

4. 19/20 - 3/25: To subtract 3/25 from 19/20, we need to find a common denominator. The LCM of 20 and 25 is 100. We can then convert both fractions to have a denominator of 100 and perform the subtraction.

The calculation is as follows: ``` 19/20 - 3/25 = (19*5)/(20*5) - (3*4)/(25*4) = 95/100 - 12/100 = 83/100 ```

Therefore, 19/20 - 3/25 = 83/100.

By finding the common denominators and performing the subtractions, we have calculated the results for each expression. If you have any further questions or need additional explanations, feel free to ask!