(3* square root of 2) square= (3* square root of 2) * (3* square root of 2)
now lets remove the brackets
remember to multiply the number outside the square root; so gives us 33 =9
and then multiplythe number inside the square root; (square root of2 * square root of 2) = square root of 4
therefore, so far we have,
9 square root of 4
(as we already know, square root of 4 = 2)
so the final result will be to do: 9* 2 = 18