Question

已知a分之1+b分之1=5a不等于b求b小括号a-b分之a-a小括号a-b分之b的值

Answer 1

解：
1/a +1/b=5
(a+b)/(ab)=5

a/[b(a-b)] -b/[a(a-b)]
=(a/b -b/a)/(a-b)
=[(a²-b²)/(ab)]/(a-b)
=(a+b)(a-b)/[ab(a-b)]
=(a+b)/(ab)
=5