1)根号8分之(根号50+根号32)-4;
=2√2分之(5√2+4√2)-4
=2√2分之9√2-4
=2分之9-4
=2分之1
2)根号6分之(根号24+根号216)+5;
=√6分之(2√6+6√6)+5
=√6分之8√6+5
=8+5
=13
3)(根号6-2根号15)×根号3-6根号2分之1;
=(√6-2√15)*√3-6*2分之√2
=3√2-6√5-3√2
=-6√5
4)根号3分之2-4根号216+42根号6分之1
=3分之√6-4√6+42*6分之√6
=3分之√6+3√6
=3分之10√6