Ta có: a+b+c=0 => a+b=-c;b+c=-a;a+c=-b
=>\(A=\left(1+\frac{a}{b}\right)\left(1+\frac{b}{c}\right)\left(1+\frac{c}{a}\right)=\frac{b+a}{b}.\frac{c+b}{c}.\frac{a+c}{a}=\frac{-c}{b}.\frac{-a}{c}.\frac{-b}{a}=-1\)
Có ai giúp mình bài toán với Cần làm gấp
Ta có a+b+c = 0 => a = -b-c ; b=-a-c ; c=-a-b
thế vào đề , ta có :
\(\left(1+\frac{-b-c}{b}\right)\left(1+\frac{-a-c}{c}\right)\left(1+\frac{-a-b}{a}\right)\)b)
<=> \(\left(\frac{b-b-c}{b}\right)\left(\frac{c-a-c}{c}\right)\left(\frac{a-b-a}{a}\right)\)
<=> \(\frac{-c}{b}\frac{-a}{c}\frac{-b}{a}\)
<=> \(\frac{-\left(a\cdot b\cdot c\right)}{a\cdot b\cdot c}\)= -1
Vậy A= -1