Please tell the solution of question 1 part 2 and 5 and how the answer is coming ??

$$\begin{gathered} \mathrm{Dear} \mathrm{Student}, \\ \mathrm{part} 2: \\ \left(3+\sqrt{23}\right)-\sqrt{23}= 3+\sqrt{23}-\sqrt{23} \\ = 2-0 = 2 \\ \mathrm{and} \mathrm{we} \mathrm{know} \mathrm{that} 2 \mathrm{is} \mathrm{a} \mathrm{rational} \mathrm{number} \mathrm{as} \mathrm{Natural} \mathrm{numbers} \mathrm{are} \mathrm{rational} \\ \mathrm{number}. \\ \mathrm{part} 5 : \\ 2\mathrm{\pi } \mathrm{now} = 2 \times \mathrm{\pi } = \mathrm{rational}\times \mathrm{\pi } \end{gathered}$$
Now we normally take pi = 22/7 but its not true. We can see that 22/7 = 3.142857142857....

  its recurring and so rational number also.

But  Pi  is not exactly equal to 22/7 , it is very close to . That's why we say that is irrational as we do not know the exact value of .So 2 * Pi = rational * irrational = Irrational number.

Regards