How do I subtract the following mixed fraction with different denominators?
The problem is 91 1/4 - 87 2/3. Do I borrow from the whole number after I solve the fraction portion?
Just change the fractions to like bases.
91 (3/12) - 87 (8/12)
4 (-5/12)
Now borrow from the whole number. Take 1, or 12/12, so that the fraction isn’t negative:
3 (7/12)
3 and 7/12 is the answer
February 10th, 2010 at 11:24 am
Just change the fractions to like bases.
91 (3/12) - 87 (8/12)
4 (-5/12)
Now borrow from the whole number. Take 1, or 12/12, so that the fraction isn’t negative:
3 (7/12)
3 and 7/12 is the answer
References :
February 10th, 2010 at 12:10 pm
The first that must happen is that both fraction must have the same denominator. We need to find the least common multiple of 4 and 3, which is 12. Also, both fractions must be improper fractions.
91 1/4 = 365/4. (365 = (91×4) + 1) and 87 2/3 = 263/3 (263 = (87×3) + 2).
Now change both fractions into fractions that have the same denominator. 365/4 = 1095/12 and 263/3 = 1052/12. So subtracting the two fractions, we get 1095/12 - 1052/12 = 43/12 or 3 7/12.
References :
February 10th, 2010 at 12:45 pm
Instead of what you’re thinking, you can turn both numbers into improper fractions, which would be 365/4 - 263/3. Then, you find the LCD, which is 12. Change the denominators to 12, and remember- whatever you do to the fraction, do it to BOTH numbers. The problem is now 1095/12 - 1052/12. subtract and get 43/12. change to a mixed number, simplify as much as possible, and there’s the answer. It’s 3 7/12
References :