已知1/a+1/b=根号5（a≠b),求a/b（a-b)-b/a（a-b)值

Question

已知1/a+1/b=根号5（a≠b),求a/b（a-b) - b/a（a-b)值

Answer 1

=a²/ab(a-b)-b²/ab(a-b)
=(a²-b²)/ab(a-b)
=(a+b)(a-b)/ab(a-b)
=(a+b)/ab
=1/a+1/b
=√5