Prove that $|R-Z|=|R|$ where $R$ is reals and $Z$ is integers.
New approach
Maybe the problem is reduced to finding a bijection between (0,1) and [0,1] if we find a bijection between these intervals, we can do the same thing for the other ones
What about this possible bijective function f(x)=1/(x-1)x
Thank you so much for your help, I have more problems like this to work on, so need more help.
Answer
Assume it is known that any open, nonempty subset of $\mathbb{R}$ is uncountable - this step is where your work may be. The rest is easy:
Let $S = \mathbb{R} \setminus \mathbb{Z}$.
First remark that $S \subset \mathbb{R}$, so we must have that $|S| \leq |\mathbb{R}|$.
The open interval $(0, 1)$ is a subset of $S \subset \mathbb{R}$, so $|(0, 1)| \leq |S| \leq |\mathbb{R}|$.
But $|\mathbb{R}| = |(0, 1)|$, and we're done.
NOTE: to see that $|\mathbb{R}| = |(0, 1)|$, we might construct a bijection $f:(0, 1) \longrightarrow (0, \infty)$ such that $f(x) = \frac{1}{1 - x} - 1$, and reason that this bijection can be easily extended to a bijection between $(0, 1)$ and $\mathbb{R}$.
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