√5(分母)分之√20+√5(分子)-2

问题描述:

√5(分母)分之√20+√5(分子)-2

√5(分母)分之√20+√5(分子)-2
=(√20+√5)/√5-2
=(2√5+√5)/√5-2
=3√5/√5-2
=3-2
=1