化简:(1)(1+根号2)(1-根号3);(2)(√5-√20)/√125
问题描述:
化简:(1)(1+根号2)(1-根号3);(2)(√5-√20)/√125
答
(1+√2)(1-√3)
=1-√3+√2-√6
(√5-√20)/√125
=√5÷√125-√20÷√125
=1/√25-√4/√25
=1/5-2/5
=-1/5