\(\frac{a}{ab+a+2}\)+ \(\frac{b}{bc+b+1}\)+ \(\frac{2c}{ac+2c+2}\)

= \(\frac{a}{ab+a+2}\)+ \(\frac{ab}{a\left(bc+b+1\right)}\)+ \(\frac{2abc}{ab\left(ac+2c+2\right)}\)

= \(\frac{a}{ab+a+2}\)+ \(\frac{ab}{abc+ab+a}\)+ \(\frac{2abc}{a^2bc+2abc+2ab}\)

= \(\frac{a}{ab+a+2}\)+ \(\frac{ab}{ab+a+2}\)+ \(\frac{2}{ab+a+2}\)   (vì  abc = 2  )

= \(\frac{ab+a+2}{ab+a+2}\)= 1

tại sao lại nhân vs a và ab z bn

M\(=\dfrac{a}{ab+a+2}+\dfrac{b}{bc+b+1}+\dfrac{2c}{ac+2c+2}\)

\(M=\dfrac{a}{ab+a+abc}+\dfrac{b}{bc+b+1}+\dfrac{2bc}{b\left(ac+2c+2\right)}\)

M = \(\dfrac{a}{a\left(b+1+bc\right)}+\dfrac{b}{b+1+bc}+\dfrac{2bc}{abc+2bc+2b}\)

M=\(\dfrac{1}{b+1+bc}+\dfrac{b}{b+1+bc}+\dfrac{2bc}{2+2bc+2b}\)

M = \(\dfrac{1+b}{b+1+bc}+\dfrac{2bc}{2\left(1+bc+b\right)}\)

M = \(\dfrac{1+b}{b+1+bc}+\dfrac{bc}{b+1+bc}=\dfrac{1+b+bc}{b+1+bc}=1\)

thế abc=2 vào M ta có 

M=\(\frac{a}{ab+b+abc}\)+ \(\frac{b}{bc+b+1}\)+ \(\frac{abc^2}{ac+abc^2+abc}\)

M=\(\frac{a}{a\left(bc+b+1\right)}\)+\(\frac{b}{bc+b+1}\)+ \(\frac{abc^2}{ac\left(bc+b+1\right)}\)

M=\(\frac{bc+b+1}{bc+b+1}\)=1

1 nha bạn cho mình nha

moi hok lop 6

34247 nhe nhé chúc mừng năm mới

trả lời dầy đủ cho mình vs nha

\(A=\frac{a}{ab+a+2}+\frac{b}{bc+b+1}+\frac{2c}{ac+2c+2}\)

\(=\frac{a}{ab+a+abc}+\frac{b}{bc+b+1}+\frac{abc^2}{ac+abc^2+abc}\)

\(=\frac{a}{a\left(bc+b+1\right)}+\frac{b}{bc+b+1}+\frac{abc^2}{ac\left(bc+b+1\right)}\)

\(=\frac{1}{bc+b+1}+\frac{b}{bc+b+1}+\frac{bc}{bc+b+1}\)

\(=\frac{bc+b+1}{bc+b+1}=1\)

Vì \(abc=2\)nên ta có:

\(M=\frac{a}{ab+a+2}+\frac{b}{bc+b+1}+\frac{2c}{ac+2c+2}\)

\(=\frac{a}{ab+a+abc}+\frac{b}{bc+b+1}+\frac{abc.c}{ac+abc.c+abc}\)

\(=\frac{a}{a\left(b+1+bc\right)}+\frac{b}{bc+b+1}+\frac{abc^2}{ac\left(1+bc+b\right)}\)

\(=\frac{1}{bc+b+1}+\frac{b}{bc+b+1}+\frac{bc}{bc+c+1}\)

\(=\frac{1+b+bc}{bc+c+1}=1\)

câu trả lời;

cho mình xửa lại một chút nha:tính :  A=\(\frac{a}{ab+a+2}+\frac{b}{bc+b+1}+\frac{2c}{ca+2c+2}\)

Ta có ; \(\frac{a}{ab+a+2}\)+\(\frac{b}{bc+b+1}\)+\(\frac{c}{ac+2c+2}\)

=\(\frac{a}{ab+a+2}\)+\(\frac{ab}{abc+ab+a}\)+\(\frac{c}{ac+2c+abc}\)

=\(\frac{a}{ab+a+2}\)+\(\frac{ab}{a+ab+2}\)+\(\frac{c}{c\left(a+2+ab\right)}\)

=\(\frac{a}{ab+a+2}\)+\(\frac{ab}{a+ab+2}\)+\(\frac{1}{a+ab+2}\)

=\(\frac{a+ab+1}{ab+a+2}\)

Đề bài này hình như có gì sai bạn ạ

đáng ra phải là \(\frac{2c}{ac+2c+2}\) chứ

À xin lỗi nha mình nhập sai. đúng là : \(\frac{2c}{ac+2c+2}\)