Question

1/a＋1/b=-4/(a+b),求(b/a)+(a/b)的值。ps:/为分数线。好心的大哥大姐帮帮我作一下，过程要详细不要方程

Answer 1

(1) 1/a＋1/b=-4/(a+b)
等式两边同时乘以(a+b),得
(a+b)b+a(a+b))=4ab,
ab+bb+aa+ab=4ab,
aa+bb=2ab
(a-b)(a-b)=0
a=b
(2) 求(b/a)+(a/b)的值
由(1)得，a=b
故(b/a)+(a/b)=1+1=2

Answer 2

1/a＋1/b=-4/(a+b)
(a+b)²/ab=-4
(a²+2ab+b²)/ab=-4
(a²+b²)/ab=-6
a/b+b/a=-6

Answer 3

1/a+1/b=-4/(a+b)
(a+b)/(ab)=-4/(a+b)
(a+b)^2=-4ab
a^2+2ab+b^2=-4ab
a^2+b^2=-6ab

b/a+a/b
=(a^2+b^2)/(ab)
=-6ab/(ab)
=-6