Question

What is 8/36 minus 3/14? Subtracting unlike fractions

Answer 1

I have a photo that shows how I got the answer and what the answer is (Key: Red represents my work, while highlighter shows what the answer is):

Answer 2

Answer: 1 / 126

Explanation:

To subtract fractions with differen denominators you must convert to equivalent fractions with the same denominator.

The best practice is to convert to fractions with the least common denominator.

Given that 8/36 is not the simplest form, you can start to simplify it, by dividing both numerator and denominator by 4:

8/36 = 2/9

Now find the least common denominator of 9 and 14. That is found by decomposing the numbers and taking the product of  the common and not common prime  factors each raised to the its greates power.

  9 = (3^2)
14 = (2)(7)

Therefore the least common denominator is: (2)(3^2)(7) = 126

So, convert both fractions to the equivalent fraction with denominator 126:

2 * 14           28
---------- =  ----------
9 * 14         126

 3 * 9        27
-------- = --------
14 * 9      126

Now you subtract the two fractions with the same denominator:

  28        27         1
------ -  ------- = -------
126      126       126

Answer: 1/126