[(a^2-b^2)/(a^2b+ab^2)]÷[(a^2+b^2)/(2ab)-1]
=(a+b)(a-b)/ab(a+b)÷[(a^2+b^2-2ab)/(2ab)]
=(a+b)(a-b)/ab(a+b) × 2ab/[(a-b)²]
=2/(a-b)
=2/(3+√5-3+√5)
=2/(2√5)
=1/√5
=√5/5
[(a^2-b^2)/(a^2b+ab^2)]÷[(a^2+b^2)/(2ab)-1]
=(a+b)(a-b)/ab(a+b)÷[(a^2+b^2-2ab)/(2ab)]
=(a+b)(a-b)/ab(a+b) × 2ab/[(a-b)²]
=2/(a-b)
=2/(3+√5-3+√5)
=2/(2√5)
=1/√5
=√5/5