First, rewrite each of the radicals as:
#(sqrt(25 * 3) - sqrt(9 * 3))/sqrt(4 * 3)#
Next, use this rule for exponents to simplify each of the radicals:
#sqrt(color(red)(a) * color(blue)(b)) = sqrt(color(red)(a)) * sqrt(color(blue)(b))#
#(sqrt(color(red)(25) * color(blue)(3)) - sqrt(color(red)(9) * color(blue)(3)))/sqrt(color(red)(4) * color(blue)(3)) =>#
#(sqrt(color(red)(25))sqrt(color(blue)(3)) - sqrt(color(red)(9))sqrt(color(blue)(3)))/(sqrt(color(red)(4))sqrt(color(blue)(3))) =>#
#(5sqrt(color(blue)(3)) - 3sqrt(color(blue)(3)))/(2sqrt(color(blue)(3)))#
Next, factor out the common term in the numerator:
#((5 - 3)sqrt(color(blue)(3)))/(2sqrt(color(blue)(3))) =>#
#(2sqrt(color(blue)(3)))/(2sqrt(color(blue)(3))) =>#
#1#