Question

Rút gọn biểu thức :

\(A=\frac{1}{\left(a-b\right)\left(a-c\right)}+\frac{1}{\left(b-a\right)\left(b-c\right)}+\frac{1}{\left(c-a\right)\left(c-b\right)}\)

Mình cần cách làm chứ kết quả thì mình biết rồi .

Answer 1

\(A=\frac{1}{\left(a-b\right)\left(a-c\right)}+\frac{1}{\left(b-a\right)\left(b-c\right)}+\frac{1}{\left(c-a\right)\left(c-b\right)}\)

\(A=\frac{1}{\left(a-b\right)\left(a-c\right)}-\frac{1}{\left(a-b\right)\left(b-c\right)}+\frac{1}{\left(a-c\right)\left(b-c\right)}\)

\(A=\frac{\left(b-c\right)-\left(a-c\right)+\left(a+b\right)}{\left(a-b\right)\left(a-c\right)\left(b-c\right)}\)

\(A=\frac{b-c-a+c+a-b}{\left(a-b\right)\left(a-c\right)\left(b-c\right)}\)

\(A=\frac{0}{\left(a-b\right)\left(a-c\right)\left(b-c\right)}\)

\(A=0\)

Đúng thì tick nha!!!

Answer 2

A=\(\frac{1}{\left(a-b\right)\left(a-c\right)}-\frac{1}{\left(a-b\right)\left(b-c\right)}+\frac{1}{\left(a-c\right)\left(b-c\right)}\)

\(A=\frac{b-c}{\left(a-b\right)\left(a-c\right)\left(b-c\right)}-\frac{a-c}{\left(a-b\right)\left(b-c\right)\left(a-c\right)}+\frac{a-b}{\left(a-c\right)\left(b-c\right)\left(a-b\right)}\)

A=\(\frac{\left(b-c\right)-\left(a-c\right)+\left(a-b\right)}{\left(a-b\right)\left(a-c\right)\left(b-c\right)}\)

A=0

Answer 3

quy đồng lên bn

Answer 4

Bạn có cách giải ko trình bày .