2021^1=2021 đk ạ??

(6/4)*5=7.5

Nghĩ đc v thui

ai giúp với mik cần gấp 

thank nha :3

ta có \(\frac{m+n}{12}=\frac{n+p}{4}=\frac{p+m}{3}=k\)(chia tất cả cho 12)

       \(\Rightarrow m+n=12k;n+p=4k;p+m=3k.\)

       \(\Rightarrow2\left(m+n+p\right)=19k\Rightarrow m+n+p=9,5k\)

       \(\Rightarrow m=5,5k;n=6,5k;p=-2,5k\)

        \(\Rightarrow9m=49,5k;8n+p=52k+\left(-2,5k\right)=49,5k\)

Mà 49,5k=49,5k nên 9m=8n+p với\(k\inℚ\)

Lấy F đối xứng A qua M, Xét \(\Delta MDF\) và \(\Delta MEA\)

MD=ME; MF=MA

\(\widehat{DMF}=\widehat{EMA}\)(góc đối đỉnh)

\(\Rightarrow\Delta MDF=\Delta MEA\left(c.g.c\right)\Rightarrow DF=EA\)

Mà EA=AC => AC=DF

Ta có 

\(\widehat{CAB}+\widehat{EAD}=360^o-\left(\widehat{EAC}+\widehat{DAB}\right)=360^o-\left(90^o+90^o\right)=180^o\)

Xét \(\Delta ADE\) có

\(\widehat{EAD}+\widehat{DEA}+\widehat{EDA}=180^o\)

\(\Rightarrow\widehat{CAB}=\widehat{EDA}+\widehat{DEA}\)

Mà \(\Delta MDF=\Delta MEA\left(cmt\right)\Rightarrow\widehat{FDE}=\widehat{DEA}\)

\(\Rightarrow\widehat{CAB}=\widehat{EDA}+\widehat{FDE}=\widehat{FDA}\)

Xét \(\Delta DFA\)và \(\Delta ABC\) có

DF=AC (cmt); DA=AB (gt)

\(\widehat{CAB}=\widehat{FDA}\left(cmt\right)\)

\(\Rightarrow\Delta DFA=\Delta ABC\left(c.g.c\right)\Rightarrow\widehat{A_1}=\widehat{B_1}\)

Mà \(\widehat{A_1}+\widehat{A_2}=180^o-\widehat{BAD}=180^o-90^o=90^o\)

\(\Rightarrow\widehat{B_1}+\widehat{A_2}=90^o\) => \(\Delta AHB\) vuông tại H \(\Rightarrow AH\perp BC\Rightarrow MA\perp BC\)