Literal Equation Solution / Explanation

[Guest]

(c / z) - (d / z) = 50

Solve for z.

c - d = 50z

50z = c - d

z = (c - d) / 50

Substitute for z in original.

c /( c - d) / 50 - d / (c - d) / 50

50c /( c - d) - 50d ( c - d) = 50 **

50c - 50d /( c - d) = 50z *

50 (c - d) /( c - d) = 50

50 = 50

Please explain:

** This step.

* "z" was added back in this step.

[Guest]

Please reply. Thanks.

[Guest]

[tex]z = \frac{c - d}{50}[/tex]

This is correct.

[Guest]

50c /( c - d) - 50d ( c - d) = 50 **

50c - 50d /( c - d) = 50z *


** Explain this step.

* Explain reason 'z' was added back in this step.

Thanks.

[Guest]

Adding that z is not correct I would say it is a spelling error.

50c /( c - d) - 50d ( c - d) = 50

(50c-50d) /( c - d) = 50

50(c-d) /( c - d) = 50

50 = 50