3/ She said that she didn't like that film

4/She said that they had gone swimming that day

5/She said that she would see Mary on Sunday

6/He said that he met her about three months before 

7/She said that Peter and Sue were getting married the next day

8/He said that Stephen was bringing some records to the party tonight

9/She said that she really liked that furniture

10/She said that her parents were arriving the next day

11/They said that they had visited her that morning

b: Xét ΔOAM và ΔOBM có 

OA=OB

\(\widehat{AOM}=\widehat{BOM}\)

OM chung

Do đó: ΔOAM=ΔOBM

Đặt \(\left\{{}\begin{matrix}n+1=a^2\\n+6=b^2\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}n=a^2-1\\n=b^2-6\end{matrix}\right.\Rightarrow a^2-1=b^2-6\)

\(\Rightarrow a^2-b^2=-6+1=-5\\ \Rightarrow\left(a-b\right)\left(a+b\right)=-5\cdot1=-1\cdot5\)

Vì \(n+1< n+6\Rightarrow a< b\Rightarrow a-b< a+b\)

\(\Rightarrow\left[{}\begin{matrix}\left\{{}\begin{matrix}a-b=-1\\a+b=5\end{matrix}\right.\\\left\{{}\begin{matrix}a-b=-5\\a+b=1\end{matrix}\right.\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}\left\{{}\begin{matrix}a=2\\b=3\end{matrix}\right.\\\left\{{}\begin{matrix}a=-2\\b=3\end{matrix}\right.\end{matrix}\right.\Rightarrow n=3\)

\(\dfrac{\sqrt{14}-\sqrt{7}}{1-\sqrt{2}}=\dfrac{14-7}{1-2}=\dfrac{7}{-1}=-7\)

\(\dfrac{\sqrt{14}-\sqrt{7}}{1-\sqrt{2}}=\dfrac{\sqrt{7}\left(\sqrt{2}-1\right)}{-\left(\sqrt{2}-1\right)}=\dfrac{\sqrt{7}}{-1}=-\sqrt{7}\)

helppp mình biết kết quả nhưng không biết cách làm:(

Gọi Vận tốc dự định của oto là x ( x>0 )
Vận tốc thực tế của oto là : x - 10
Thời gian dự định của oto đến HP là : 2h30' = 2,5h
Thời gian thực tế của oto đến HP là : 3h30' = 3,5h
Theo bài ra ta có PT :
2,5x = ( x - 10 ) . 3,5
<=> 2,5x = 3,5x - 35
<=> -x = -35 <=> x = 35
Vậy vận tốc dự định của oto là 35 km/h nên quãng đường AB là : 35.2,5 = 87,5 km

nguồn :http://hoctap.info/threads/8360-Moi-nguoi-thu-la-may-bai-toan-bang-cach-TPT-nay-thu-xem.html

\(\left(2x-1\right)^2+\left(x+3\right)^2-5\left(x+7\right)\left(x-7\right)=0\\ 4x^2-4x+1+x^2+6x+9-5x^2+245=0\\ 2x+255=0\\ 2x=-255\\ x=-\dfrac{255}{2}\)