(X^24) - (x^-1) = X^23 ... How?

[mikuumi]

Hi,

This is probably really simple but I just don't understand it.

So the teacher "says" that:
(X^24) - (X^-1) = X^23

But isn't (X^24) times (X^-1) = X^23

I would really appreciate if someone would clear how the first equation is true, or if it isn't true and the teacher has made an error.

 

[Deleted member 4993]

Hi,

This is probably really simple but I just don't understand it.

So the teacher "says" that:real s
(X^24) - (X^-1) = X^23

But isn't (X^24) times (X^-1) = X^23

I would really appreciate if someone would clear how the first equation is true, or if it isn't true and the teacher has made an error.

Let's assume that the first equation is true under certain conditions (for certain values of 'x'). Also \(\displaystyle x \ne 0\).Then:

x^25 - 1 = x^24

There is no rational solution to this equation. There is only one real solution to the equation (and 24 complex solution).

So yes - most probably that "-" was meant to be "*".