I write two quadratic surds whose sum is a rational number.

Given: two quadratic surds

A quadratic surd is an expression containing square roots, such that number under square root is a rational number and is not a perfect square.

Let we take quadratic surds as:

7-√3 and 7 + √3

Sum of these surds will be:

7-√3 + 7 + √3

= 14

Where 14 is a rational number.