Question

Объясните как выполнить сложение и вычитание дробей с разными знаменателями! Очень надо

Answer 1

Привести их к общему знаменателю. 
а потом уже складывать/вычитать. 

Answer 2

Addition of Fractions with Different Denominators

When adding fractions with different denominators, you need to find a common denominator before performing the addition. Here's a step-by-step process to follow:

1. Find the least common multiple (LCM) of the denominators. The LCM is the smallest number that is divisible by both denominators. 2. Rewrite each fraction with the common denominator. 3. Add the numerators of the fractions. 4. Keep the common denominator. 5. Simplify the fraction, if possible.

Let's look at an example:

Example:

Add 2/5 and 4/7.

1. The denominators are 5 and 7. The LCM of 5 and 7 is 35. 2. Rewrite the fractions with the common denominator: - 2/5 becomes 14/35 (multiply the numerator and denominator of 2/5 by 7). - 4/7 remains the same. 3. Add the numerators: 14 + 4 = 18. 4. Keep the common denominator: 35. 5. The result is 18/35.

Therefore, 2/5 + 4/7 = 18/35.

Subtraction of Fractions with Different Denominators

Subtracting fractions with different denominators follows a similar process as addition. Here's how you can do it:

1. Find the least common multiple (LCM) of the denominators. 2. Rewrite each fraction with the common denominator. 3. Subtract the numerators of the fractions. 4. Keep the common denominator. 5. Simplify the fraction, if possible.

Let's see an example:

Example:

Subtract 6/11 from 3/4.

1. The denominators are 11 and 4. The LCM of 11 and 4 is 44. 2. Rewrite the fractions with the common denominator: - 3/4 becomes 33/44 (multiply the numerator and denominator of 3/4 by 11). - 6/11 remains the same. 3. Subtract the numerators: 33 - 6 = 27. 4. Keep the common denominator: 44. 5. The result is 27/44.

Therefore, 3/4 - 6/11 = 27/44.

Remember to always simplify the fraction if possible.

I hope this explanation helps! Let me know if you have any further questions.