Add. Write your answer in simplest form.
negative 9 radical 2 plus 8 radical 2
To add numbers with radicals, you combine like terms. In this case, you have -9√2 and +8√2. Since they both have √2 as their radical part, you just add the coefficients.
-9√2 + 8√2 = (-9 + 8)√2 = -1√2
In simplest form, the result is -√2.