Question

一直b/a+a/b=2,求a平方-3ab+b平方/a平方-7ab-b平方的值

Answer 1

/a+a/b=2二边平方得:b^2/a^2+2b/a*a/b+b^2/a^2=4即b^2/a^2+b^2/a^2=2(b/a-a/b)^2=b^2/a^2-2b/a*a/b+a^2/b^2=2-2=0故b/a-a/b=0[a²-3ab+b²]/[a²-7ab-b²].(分子分母同除以ab)=(a/b-3+b/a)/(a/b-b/...