Answer:
1) 1/2 + 1/4 = 2/4 + 1/4 = 3/4
2) To add these fractions, you need to find a common denominator. The smallest common multiple of 7 and 9 is 63, so we can write:
3/7 * 9/9 + 2/9 * 7/7 = 27/63 + 14/63 = 41/63
3) To add these fractions, you need to find a common denominator. The smallest common multiple of 5 and 15 is 15, so we can write:
3/5 * 3/3 + 1/15 * 1/1 = 9/15 + 1/15 = 10/15
But we can simplify this fraction by dividing both the numerator and denominator by 5:
10/15 = 2/3
4) To add these fractions, you need to find a common denominator. The smallest common multiple of 9 and 8 is 72, so we can write:
1/9 * 8/8 + 7/8 * 9/9 = 8/72 + 63/72 = 71/72
5) To add these fractions, you need to find a common denominator. The smallest common multiple of 7 and 21 is 21, so we can write:
6/7 * 3/3 + 2/21 * 1/1 = 18/21 + 2/21 = 20/21
6) To add these fractions, we need to find a common denominator first. The smallest number that both 6 and 10 divide into is 30. So, we convert 4/6 to 20/30 by multiplying both the numerator and denominator by 5, and we convert 2/10 to 3/15 by multiplying both the numerator and denominator by 3. Now we have:
20/30 + 3/15 = (20x1 + 3x2)/(30x2) = 23/60
Therefore, 4/6 + 2/10 = 23/60.
7) To add these fractions, we need to find a common denominator first. The smallest number that both 11 and 22 divide into is 22. So, we convert 1/11 to 2/22 by multiplying both the numerator and denominator by 2, and we convert 3/22 to 3/22 (it is already in terms of 22). Now we have:
2/22 + 3/22 = (2 + 3)/22 = 5/22
Therefore, 1/11 + 3/22 = 5/22.
8) To add these fractions, we need to find a common denominator first. The smallest number that both 4 and 20 divide into is 20. So, we convert 1/4 to 5/20 by multiplying both the numerator and denominator by 5, and we convert 8/20 to 8/20 (it is already in terms of 20). Now we have:
5/20 + 8/20 = (5 + 8)/20 = 13/20
Therefore, 1/4 + 8/20 = 13/20.
9) To add these fractions, we need to find a common denominator first. The smallest number that both 7 and 9 divide into is 63. So, we convert 4/7 to 24/63 by multiplying both the numerator and denominator by 3, and we convert 2/9 to 14/63 by multiplying both the numerator and denominator by 7. Now we have:
24/63 + 14/63 = (24 + 14)/63 = 38/63
Therefore, 4/7 + 2/9 = 38/63.
10) To add these fractions, we need to find a common denominator first. The smallest number that both 10 and 30 divide into is 30. So, we convert 6/7 to 18/30 by multiplying both the numerator and denominator by 3, and we convert 2/30 to 1/15 by multiplying both the numerator and denominator by 15. Now we have:
18/30 + 1/15 = (18x1 + 1x2)/(30x2) = 37/30
Therefore, 6/7 + 2/21 = 37/30.