Bn kia nhận lm r` h mk lm đc k???
(thoy, chán quá ~~~ mk lm lun nhá)
Sửa đề: cho 2 góc kề nhau: góc xOy và....
a/Có: \(\widehat{xOy}+\widehat{yOz}=150^o;\widehat{xOy}-\widehat{yOz}=30^o\)
=> \(\widehat{xOy}=\dfrac{150^o+30^o}{2}=90^o\)
\(\widehat{yOz}=90^o-30^o=60^o\)
Vậy .....................................
b/ Có: \(\widehat{O_1}=\widehat{O_2}\left(gt\right)\Rightarrow\widehat{O_2}=\dfrac{1}{2}\widehat{xOy}=45^o\)
\(\widehat{O_3}=\widehat{O_4}\left(gt\right)\Rightarrow\widehat{O_3}=\dfrac{1}{2}\widehat{yOz}=30^o\)
\(\Rightarrow\widehat{mOn}=\widehat{O_2}+\widehat{O_3}=45^o+30^o=75^o\)
Vậy.....................