Giải thích các bước giải:

Bài 1:

Ta có:

$\widehat{xOy}+\widehat{yOz}=180^o$ vì $\widehat{xOy}, \widehat{yOz}$ kề bù

$\to 3\widehat{yOz}+\widehat{yOz}=180^o$

$\to 4\widehat{yOz}=180^o$

$\to \widehat{yOz}=45^o$

$\to \widehat{nOz}=\widehat{nOy}=\dfrac12\widehat{yOz}=22.5^o$

$\to \widehat{xOn}=180^o-\widehat{zOn}= 157.5^o$

Bài 2:

a.Ta có:

$\widehat{xOz}+\widehat{yOz}=\widehat{xOy}=150^o$

$\to 2\widehat{yOz}+\widehat{yOz}=150^o$

$\to 3\widehat{yOz}=150^o$

$\to \widehat{yOz}=50^o$

$\to \widehat{xOz}=\widehat{xOy}-\widehat{yOz}=100^o$

b.Vì $Om$ là phân giác $\widehat{xOz}$

$\to \widehat{mOx}=\widehat{mOz}=\dfrac12\widehat{xOz}=50^o=\widehat{yOz}$

$\to Oz$ là phân giác $\widehat{mOy}$