Question

数学题!~~不太会做!~~帮一下忙!~~过程详细!~~谢谢!~~

Answer 1

a/a+b + b/a-b - a*a/a*a-b*b

=a(a-b)+b(a+b)/(a^2-b^2)-a^2/(a^2-b^2)

=b^/(a^2-b^2)

3a=4b=12k

a=4k

b=3k

原式=(3k)^2/(4k)^2-(3k)^2

=9k^2/7k^2

=9/7