Question

Lm 1 bài cx đc, giúp mk nha mk cần gấp

Answer 1

Ko đây là bài thi mà :>

Answer 2

Answer 3

Câu 5:

\(\dfrac{a}{2019}=\dfrac{b}{2021}=\dfrac{a-b}{-2}\\ \dfrac{b}{2021}=\dfrac{c}{2023}=\dfrac{b-c}{-2}\\ \dfrac{a}{2019}=\dfrac{c}{2023}=\dfrac{a-c}{-4}\\ \Leftrightarrow\dfrac{a-b}{-2}=\dfrac{b-c}{-2}=\dfrac{a-c}{-4}\\ \Leftrightarrow2\left(a-b\right)=2\left(b-c\right)=a-c\\ \Leftrightarrow\left(a-c\right)^2=4\left(b-c\right)^2=4\left(b-c\right)\left(a-b\right)\\ \Leftrightarrow\dfrac{\left(a-c\right)^2}{4}=\left(b-c\right)\left(a-b\right)\)