当a+2b分之a-2b等于4时,求代数式4(a+2b)分之3（a-2b)+(a-2b)分之3(a+2b)的值我急啊!麻烦大家帮帮忙!谢谢!

Question

当a+2b分之a-2b等于4时,求代数式4(a+2b)分之3（a-2b)+(a-2b)分之3(a+2b)的值
我急啊!麻烦大家帮帮忙!谢谢!

Answer 1

(a-2b)/(a+2b)=4
即A-2B=4A+8B ==>-3A=10B ==>A=-10B/3
则3（a-2b)/(4(a+2b))+3(a+2b)/(a-2b)
=3(-10B/3-2B)/(4(-10B/3+2B)+3(-10B/3+2B)/(-10B/3-2B)
=-16B/(-16B/3)+(-4B)/(-16B/3)
=3+3=6