# Math Help - solving letter only equations

1. ## solving letter only equations

solve for x

(1/x) + (1/y) = z
i multiplied by xy to get rid of the denominators:
y + x = zxy
then
x = zxy -y

from here i have no idea.....

2. As a general rule, at least 2 equations are required to solve 2 variables. At least 3 equations are required to solve 3 variables.

So unless you left out some other information, it is not possible to find a unique solution. The question most likely wants you to find x in terms of the other 2 variables, which you did well. From here, move the zxy over to the left and factorise x out.

3. guess i should have posted the answer in the back of the book eh?

x= (y/yz-1)

how did they get rid of the other x?

4. Originally Posted by t-dot
solve for x

(1/x) + (1/y) = z
i multiplied by xy to get rid of the denominators:
y + x = zxy
then
x = zxy -y

from here i have no idea.....
$\frac{1}{x} + \frac{1}{y} = z$

$\frac{1}{x} = z - \frac{1}{y}$

$x = \frac{1}{z - \frac{1}{y}}$

$x = \frac{1}{\frac{yz}{y} - \frac{1}{y}}$

$x = \frac{1}{\frac{yz - 1}{y}}$

$x = \frac{y}{yz - 1}$.

5. great help.
awesome!