# How do you add or subtract 5/(4x^2y) – y/(14xz)?

##### 1 Answer
Apr 17, 2018

We begin by trying to find a common denominator for these two fractions....
1) The two denominators that we are working with are $4 {x}^{2} y$and $14 x z$
2) To find the LCD we must factor out the two numbers
$14 x z = 2 \cdot 7 \cdot x \cdot z$
$4 {x}^{2} y = {2}^{2} \cdot {x}^{2} \cdot y$
3) Then we find the product of each factor with the highest power
$\left({2}^{2}\right) \left({x}^{2}\right) \left(7\right) \left(y\right) \left(z\right) = 28 {x}^{2} y z$

Then we try to set each denominator to the LCD that we found $\frac{28 {x}^{2} y z}{28 {x}^{2} y z}$ 28x^2yz)/(28x^2yz)
4) $\frac{5}{4 {x}^{2} y} \cdot \frac{7 z}{7 z} = \frac{35 z}{28 {x}^{2} y z}$

$\frac{y}{14 x z} \cdot \frac{2 x y}{2 x y} = \frac{2 x {y}^{2}}{28 {x}^{2} y z}$

Now since we have a common denominator, we can now simply the equation into one fraction
$\frac{35 z - 2 x {y}^{2}}{28 {x}^{2} y z}$
That took forever to write out on this,,,