Question

Answer 1

mờ quá ko thấy chi lun

 

Answer 2

\(\Rightarrow\dfrac{a-b}{-1}=\dfrac{b-c}{-1}=\dfrac{a-c}{2}\\ \Rightarrow-2\left(a-b\right)=-2\left(b-c\right)=c-a\\ \Rightarrow M=4\left(a-b\right)\left(b-c\right)-\left(c-a\right)^2=4\left(a-b\right)^2-\left(c-a\right)^2=\left[-2\left(a-b\right)\right]^2-\left(c-a\right)^2=\left(c-a\right)^2-\left(c-a\right)^2=0\)