√5(√2-√1/2)
=√5（√2-1/2√2）
=√5x1/2√2
=1/2√10
√3÷﹙1／√3＋1／√2﹚
=√3(1/√3-1/√2)÷[（1/√3+1/√2）(1/√3-1/√2)]
=(1-√3/√2)÷(1/3-1/2)
=(1-1/2√6)÷1/6
=3√6-6
﹙√30－√18﹚÷﹙√5－√3﹚－√6
=√6(√5-√3)÷(√5-√3)-√6
=√6-√6
=0