contradiction proof question

Hi! Does someone mind helping me with this question? I don't really know where to start

Begin by assuming that P is irrational and 1/P is rational.

What form can 1/P be written in?

If 1/P is rational then it can be written as a fraction i.e a/b ?

Begin by assuming that P is irrational and 1/P is rational.

What form can 1/P be written in?

For (b), are integer multiples of surds irrational or rational?

If the surd is irrational, any integer multiple of it will be irrational. It makes sense it you think about it. But for b, all you need to do is think of 2 numbers that that multiply to get a square number. For example 2 and 8. 2^1/2 mutpliplied by 8^1/2 equals 16^1/2 equals 4, which is rational

For (b), are integer multiples of surds irrational or rational?

If the surd is irrational, any integer multiple of it will be irrational. It makes sense it you think about it. But for b, all you need to do is think of 2 numbers that that multiply to get a square number. For example 2 and 8. 2^1/2 mutpliplied by 8^1/2 equals 16^1/2 equals 4, which is rational

Irrational.