Surds question grade 10 I am a student and need help answering this question. I need a step by step solution.
Simplify:
$ \sqrt {18}$ - $ \sqrt {9}$ 
What I tried:
($ \sqrt {9}$ × $ \sqrt {2}$) - 9
= (3$ \sqrt {2}$ ) - 9
I don't know what to do next.
Thank you and help is appreciated.

Here is a mistake you've made:
Going from the first step to the second step, you should have put the square root: $$\sqrt{18}-\sqrt{9} \implies (\sqrt{9}\times \sqrt{2})-\color{red}{\sqrt{9}}$$
Can you take it from here?
