Hello! Okay let me start off by explaining to how you can simplify a square root...
Let's take √12 for instance...
the factors of this number are 2, 3, 4, and 6 .... and out of these 4 numbers there is one perfect square, which is 4
so you can split √12 into ---> √4 and √3 ..... these would then simplify into 2√3
because the 4 is square rooted
now by doing the same to √18 we get ----> √9 * √2 ----> 3√2
Before we multiply the square roots we must remember that numbers underneath the square root can only be multiplied with other numbers underneath a square root....
so...
2√3 * 3√2
(2 * 3) * (√3 * √2)
6√6 <----------------------- This is your final answer!
I hope this helps! :D
Please vote me for Brainliest if there is a second answer!