If x $\dfrac{\sqrt{2}-1}{\sqrt{2}+1}$ and y = $\dfrac{\sqrt{2}+1}{\sqrt{2}-1}$ , then find the value of ${x^2 +5xy + y^2}$.

Choose the correct statement :

1. Reciprocal of every rational number is a rational number.
2. The square roots of all positive integers are irrational numbers.
3. The product of a rational and an irrational number is an irrational number.
4. The difference of a rational number and an irrational number is an irrational number.

Between two rational numbers

1. there is no rational number
2. there is exactly one rational number
3. there are infinitely many rational numbers
4. there are only rational numbers and no irrational numbers.

Decimal representation of a rational number cannot be

1. terminating
2. non-terminating
3. non-terminating repeating
4. non-terminating non-repeating