Sometimes you won't be able to, but it's usually a good idea.
Only if the problem asks you too
No because in order to subtract or add fractions the denominator of the fractions must be the same and if they are not then the lowest common denominator of the fractions must be found. Having subtracted or added the fractions then it may be possible to simplify the result.
It is easy: just convert to decimal fractions.
Possible reasons: To add or subtract fractions, To compare fractions with different denominators.
The LCD of two fractions is the same as the LCM of their denominators.
Not true. Try 1/6 + 1/3
Only if the problem asks you too
No because in order to subtract or add fractions the denominator of the fractions must be the same and if they are not then the lowest common denominator of the fractions must be found. Having subtracted or added the fractions then it may be possible to simplify the result.
Once you find the LCD, convert the fractions to their equivalents and then you can add and/or subtract them correctly.
The denominators are different, so find the equivalent fractions using the LCD , then add the fractions with the denominators.
It is easy: just convert to decimal fractions.
Possible reasons: To add or subtract fractions, To compare fractions with different denominators.
The LCD of 2/3 and 1/6 is 6. 4/6 - 1/6 = 3/6 = 1/2
The LCD of two fractions is the same as the LCM of their denominators.
The LCD for fractions is the LCM (least common multiple) of all of the denominators.
Ordinarily, one finds the least common denominator (LCD) of a set of common fractions in order to add or subtract the set of fractions. The LCD is the least common multiple (LCM) of the denominators of the set of fractions. Without knowing whatis to be multiplied by the LCD, and why, this question is ambiguous.
Adding fractions. 1/5 + 1/2 need a common denominator to add.