(15倍根号5)/(5倍根号2+2倍根号5)将分母有理化
问题描述：
(15倍根号5)/(5倍根号2+2倍根号5)将分母有理化
答
15√5/(5√2+2√5）
=15√5(5√2-2√5)/[(5√2+2√5)(5√2-2√5)]
=(75√10-150)/(50-20)
=(75√10-105)/30
=5/2√10-2