Question

Giúp với ạ!!!!!!!!

Answer 1

Câu 1: 

Đặt \(\widehat{B}=x;\widehat{C}=y\)

Theo đề, ta có: 

\(\left\{{}\begin{matrix}x+y=110\\x-y=30\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}2x=140\\x-y=30\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=70\\y=40\end{matrix}\right.\)

hay \(\widehat{A}=\widehat{B}\)