# Subtracting Fractions 1

Banned

#### TheJason

Staff member
Moderator
$$\displaystyle \dfrac{4x}{2} - \dfrac{5x}{y}$$

$$\displaystyle \dfrac{(4x)(y) - (2)(5x)}{(2)(y)} = \dfrac{(4x)(y)}{(2)(y)} - \dfrac{(2)(5x)}{(2)(y)}$$

Cancel out stuff.

$$\displaystyle \dfrac{4x}{2} - \dfrac{5x}{y} = \dfrac{2x}{1} - \dfrac{5x}{y}$$

#### TheJason

Staff member
Moderator
So @MarkFL is this one and similar ones correct?

#### MarkFL

##### La Villa Strangiato
Staff member
Moderator
Math Helper
What you want to do is combine terms...

anemone

#### TheJason

Staff member
Moderator
What answer would you get in that case? Is it the same one?

#### MarkFL

##### La Villa Strangiato
Staff member
Moderator
Math Helper
I would reduce the first term as you did and then combine:

$$\displaystyle \frac{4x}{2}-\frac{5x}{y}=\frac{2x}{1}-\frac{5x}{y}=\frac{2xy-5x}{y}=\frac{x}{y}(2y-5)$$

harpazo

#### harpazo

##### Pure Mathematics
Banned
I would reduce the first term as you did and then combine:

$$\displaystyle \frac{4x}{2}-\frac{5x}{y}=\frac{2x}{1}-\frac{5x}{y}=\frac{2xy-5x}{y}=\frac{x}{y}(2y-5)$$

#### MarkFL

##### La Villa Strangiato
Staff member
What you've ended up with is not equivalent to that with which you began. You multiplied the expression by $$2y$$ which changes it.
What you've ended up with is not equivalent to that with which you began. You multiplied the expression by $$2y$$ which changes it.