Helpp
Helpp !!!
1 I wear colorful clothes during Tet Holiday
2 I will say happy new year to my mother
3 She won't ask for lucky money
4 I won't sweep the floor
5 He won't take the things related to the house out of water
1. I wear colorful clothes during Tet Holiday.
2. I will to say happy new year.....đoạn này mk hơi bí.
3. She won't ask for lucky money.
4. I won't sweep the floor.
5. He won't take the things related to the house out of water.
1. I will wear colorful clothes during Tet holiday.
2. I will say happy new year to my mother.
3. She won't ask for lucky money.
4. I won't sweep the floor.
5. He won't take the things related to the house out of water.
helpp
Helpp
Helpp
Do M thuộc d nên tọa độ có dạng: \(M\left(2+2t;3+t\right)\)
\(\Rightarrow\overrightarrow{AM}=\left(2+2t;2+t\right)\)
\(\Rightarrow AM=\sqrt{\left(2+2t\right)^2+\left(2+t\right)^2}=\sqrt{5t^2+12t+8}\)
Mà \(AM=5\Rightarrow\sqrt{5t^2+12t+8}=5\)
\(\Rightarrow5t^2+12t+8=25\)
\(\Rightarrow5t^2+12t-17=0\Rightarrow\left[{}\begin{matrix}t=1\\t=-\dfrac{17}{5}\end{matrix}\right.\)
Với \(t=1\Rightarrow M\left(4;4\right)\) loại do hoành độ dương
Với \(t=-\dfrac{17}{5}\Rightarrow M\left(-\dfrac{24}{5};-\dfrac{2}{5}\right)\) thỏa mãn
M thuộc D nên tọa độ M có dạng (2+2a;3+a) . Vì M có hoành độ âm nên a<-1.
Theo bài ra, ta có : \(AM=5\Leftrightarrow\sqrt{\left(2+2a\right)^2+\left(2+a\right)^2}=5\)
\(\Leftrightarrow5a^2+12a-17=0\)
\(\Leftrightarrow\left[{}\begin{matrix}a=1\left(loại\right)\\a=-\dfrac{17}{5}\left(nhận\right)\end{matrix}\right.\)
Với a = -17 /5
=> \(M\left(-\dfrac{24}{5};-\dfrac{2}{5}\right)\)
Helpp
Helpp :((
Helpp!
a: Ta có: \(\widehat{ADE}=\widehat{C}\)
mà hai góc này là hai góc ở vị trí so le trong
nên DE//BC
Xét ΔBAC có \(\widehat{ABC}+\widehat{ACB}+\widehat{BAC}=180^0\)
hay \(\widehat{ABC}=50^0\left(1\right)\)
Ta có: \(\widehat{DAB}+\widehat{BAC}=180^0\)
\(\Leftrightarrow\widehat{MAB}=\dfrac{180^0-80^0}{2}=50^0\left(2\right)\)
Từ \(\left(1\right),\left(2\right)\) suy ra AM//BC
mà BC//DE
nên AM//DE
Helpp
helpp:>
A.
\(C_2H_2+H_2\xrightarrow[t^o]{Pd}C_2H_4\\ C_2H_4+H_2\xrightarrow[t^o]{Ni}C_2H_6\)