# For Fraction Addition and Subtraction - Which method is best?

#### Jason

##### Well-known member
Using LCM or the formulas like:

$\dfrac{a}{b} + \dfrac{c}{d}$
$\dfrac{(a)(d) + (b)(c)}{(b)(d)}$ etc.. (Subtraction one has a minus instead of a plus.)

The speed at doing LCM depends on how good you are finding LCM - and that could be as fast as someone knowing the formula given in this post.

#### MarkFL

##### La Villa Strangiato
Math Helper
It's hard to say which is best...I think it depends on the actual expression.