what is an eay way to add 1/5 1/2 and 1/7. I have to find a number that they all go into for a similar denominator right? but how do I do that without taking forever.
Multiply the denominators:
5 x 2 x 7 = ??
=)
As Writeacher has noted, the common denominator is 70 in this case. Convert each fraction to the equivalent value with 70 as the denominagtr, and add them.
1/5 = 14/70
1/2 = 35/70
1/7 = 10/70
To add fractions with different denominators, you are correct that you need to find a common denominator. One way to do this is to multiply all the denominators together.
In this case, the denominators are 5, 2, and 7. To find a common denominator, you can multiply these numbers together:
5 x 2 x 7 = 70
So, the common denominator is 70.
To convert each fraction to have a denominator of 70, you need to multiply the numerator and denominator of each fraction by the same value.
For 1/5, you can multiply the numerator and denominator by 14:
1/5 = (1 x 14) / (5 x 14) = 14/70
For 1/2, you can multiply the numerator and denominator by 35:
1/2 = (1 x 35) / (2 x 35) = 35/70
For 1/7, you can multiply the numerator and denominator by 10:
1/7 = (1 x 10) / (7 x 10) = 10/70
Now, all three fractions have the same denominator of 70.
To add them together, simply add the numerators:
14/70 + 35/70 + 10/70 = (14 + 35 + 10) / 70 = 59/70
So, the sum of 1/5, 1/2, and 1/7 is 59/70.