Question

已知a/(a-b)=2,求((a^2+ab)(a-5b))/((a-b)(a^2-5ab))的值

Answer 1

a/(a-b)=2

a=2a-2b

a=2b

((a^2+ab)(a-5b))/(a-b)(a^2-5ab)

=(a(a+b)(a-5b))/a(a-b)(a-5b)

=(a+b)/(a-b)

=3b/b

=3