(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

(15√5)/(5√2+2√5)
=(15√5)(5√2-2√5)
/[(5√2+2√5))(5√2-2√5)]
=√5/2*(5√2-2√5)

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