Ido not know how to figure this it looks but my mind just draws a blank

(3√8)(4√3)

1st you multiply the digits that are out of the radicand (√):

(3x4)(√8)(√3) ==> 12(√8)(√3)

2nd you multiply the radicand together (part under the square root):
√8 x √3 =√(8x3) = √24

3rd you multiply by 12 ==> 12√24
But you can simplify: if you notice that 24 = 2³ x 3
12√(2³ x3)==> 12x2√(2x3) ==> final answer 24√3