Làm thế nào để gây hứng thú với môn Sử?
(cần gấp)
BT.
1. She is bad and a always wants to hurt people . She is _______.
A. evil B. harmful C. moral D. kind
1. She is bad and a always wants to hurt people . She is _______.
A. evil (xấu xa, ác quỷ) B. harmful (có hại) C. moral (thích hợp) D. kind (hiền lành)
BT.
1. She is bad and a always wants to hurt people . She is _______.
A. evil B. harmful C. moral D. kind
What Time is the game news programme on?
Which channels do you have
Why can't I use this remote control?- Because it isn't working
How often do you watch cartoons?- Two or three time a week
Where do you go school?- I go to Trung Vuong Lower Secondary scholl
When do you have English?- On Wednesday and Friday morning
How long are you playing the video game?- For an hour
...what... Time is the game news programme on?
...what/which... channels do you have
...why... can't I use this remote control?- Because it isn't working
...how often... do you watch cartoons?- Two or three time a week
...where... do you go scholl?- I go to Trung Vuong Lower Secondary scholl
....when.. do you have English?- On Wednesday and Friday morning
...how long... are you playing the video game?- For an hour
1) Ta có: \(\left(-5+x\right)\left(x-7\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}-5+x=0\\x-7=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=5\\x=7\end{matrix}\right.\)
Vậy: \(x\in\left\{5;7\right\}\)
2) Ta có: \(\left(30-x\right)\left(2x-16\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}30-x=0\\2x-16=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}-x=-30\\2x=16\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=30\\x=8\end{matrix}\right.\)
Vậy: \(x\in\left\{30;8\right\}\)
3) Ta có: \(\left(-5-x\right)\left(17+x\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}-5-x=0\\17+x=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}-x=5\\x=0-17\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-5\\x=-17\end{matrix}\right.\)
Vậy: \(x\in\left\{-5;-17\right\}\)
4) Ta có: \(\left(-3x+18\right)\left(-5x-10\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}-3x+18=0\\-5x-10=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}-3x=-18\\-5x=10\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=6\\x=-2\end{matrix}\right.\)
Vậy: \(x\in\left\{6;-2\right\}\)
Bài nay ta có hai vế bạn hãy đặt giả sử một trong hai vế bằng 0 rồi giải phương trình cho mỗi vế bằng o
Trên tia Ox, ta có: OA<OB(4cm<8cm)
nên điểm A nằm giữa hai điểm O và B
\(\Leftrightarrow OA+AB=OB\)
\(\Leftrightarrow AB=OB-OA=8-4=4\left(cm\right)\)
Ta có: điểm A nằm giữa hai điểm O và B(cmt)
mà AB=OA(=4cm)
nên A là trung điểm của OB