\(A=\dfrac{2\left(b-c\right)\left(c-a\right)+2\left(a-b\right)\left(c-a\right)+2\left(a-b\right)\left(b-c\right)}{\left(a-b\right)\left(b-c\right)\left(c-a\right)}+\dfrac{\left(a-b\right)^2+\left(b-c\right)^2+\left(c-a\right)^2}{\left(a-b\right)\left(b-c\right)\left(c-a\right)}\)
\(=\dfrac{2\left(b-c\right)\left(c-a+a-b\right)+2\left(a-b\right)\left(c-a\right)}{\left(a-b\right)\left(b-c\right)\left(c-a\right)}+\dfrac{\left(a-b\right)^2+\left(b-c\right)^2+\left(c-a\right)^2}{\left(a-b\right)\left(b-c\right)\left(c-a\right)}\)
\(=\dfrac{-2\left(b-c\right)^2+2\left(ac-a^2-bc+ba\right)}{\left(a-b\right)\left(b-c\right)\left(c-a\right)}+\dfrac{\left(a-b\right)^2+\left(b-c\right)^2+\left(c-a\right)^2}{\left(a-b\right)\left(b-c\right)\left(c-a\right)}\)
\(=\dfrac{-2b^2+4bc-2c^2+2ac-2a^2-2bc+2ab+2a^2+2b^2+2c^2-2ab-2bc-2ac}{\left(a-b\right)\left(b-c\right)\left(c-a\right)}\)
\(=\dfrac{4ac+4ab}{\left(a-b\right)\left(b-c\right)\left(c-a\right)}\)
giúp mình bài này với ạ,ghi từng bước giúp mình lun ạ
giúp mình với ạ, mình cần gấp lắm ạ
