Number system — Question 1

$31+4\sqrt{57}$

$={\left(\sqrt{19}\right)}^2+{\left(2\sqrt{3}\right)}^2+2\times \sqrt{19}\times 2\sqrt{3}$

$={\left(\sqrt{19}+2\sqrt{3}\right)}^2$

$\text{Square}\text{root}=\sqrt{19}+2\sqrt{3}$

We can use options to get the answer.

Square the values and check which comes equal to $31+4\sqrt{57}$.