[(√3+1)(√12*5)-√15-√5]/√5
=[(√3+1)√12*√5-√15-√5]/√5
=√5[(√3+1)√12-√3-1]/√5
=(√3+1)*√12-√3-1
=(√3+1)*2√3-√3-1
=6+2√3-√3-1
=5+√3