Mọi người giúp mình với ạ
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3:
a: CD vuông góc AD
CD vuông góc SA
=>CD vuông góc (SAD)
b: BC vuông góc AB
BC vuông góc SA
=>BC vuông góc (SAB)
=>(SBC) vuông góc (SAB)
1 She likes reading books
2 What about going to Dam Sen park?
3 If people pollute the water, a lot of fish won't die
4 Peter is taller than Mary
5 We have lived here for 15 years
6 Peter told Anna that he couldn't go swimming the day after
7 His homework about natural disaster has been finished by him
8 He said that they had done an experiment
9 If Huong tidied her house, her Mom wouldn't feel angry
10 A lot of underwater animals die because of the polluted water
1. She likes reading books.
2. What about going to Dam Sen park?
3. If people pollute the water, a lot of fish will die.
4. Peter is taller than Mary.
5. We have lived here for five years.
6. Peter told Anna that he couldn't go fishing the following day.
7. His homework about natural disasters has been finished (by him).
8. They said that they had done an experiment.
9. If Huong doesn't tidy the house, her mom will feel angry.
10. A lot of underwater animals die because of the polluted water.
Ko nên ước mơ của mình là người yêu của anh Anh chuẩn bị đi làm về chưa em ơi em có thể làm được gì đâu mà đi làm về chưa em ơi em có thể làm được gì đâu mà đi làm về chưa em ơi em có
a) Ta có :
\(x - y = 5\)
\(\frac{x}{2}=\frac{y}{3}\)
Áp dụng tính chất dãy tỉ số bằng nhau , ta có :
\(\frac{x}{2}=\frac{y}{3}=\frac{x-y}{2-3}=\frac{5}{-1}=-5\)
\(\Rightarrow\hept{\begin{cases}x=-5 . 2 = -10\\y=-5.3=-15\end{cases}}\)
b) Ta có :
\(x - y = 9\)
\(\frac{x}{-2}=\frac{y}{-5}\)
Áp dụng tính chất dãy tỉ số bằng nhau , ta có :
\(\frac{x}{-2}=\frac{y}{-5}=\frac{x-y}{-2-\left(-5\right)}=\frac{9}{3}=3\)
\(\Rightarrow\hept{\begin{cases}x=3. \left(-2 \right)= -6\\y=3 . \left(-5\right) = -15\end{cases}}\)
1 If I were you I would recycle these plastic carrier bags
2 The pilots suddenly struck, so all flights had to be cancelled
3 The polluted environment causes the death of birds and plants
4 The contaminated food leads to people's poor health
Minh said he would go to China the following year
Lan said she liked learning English
Peter said he would go to the movies with me
Miss Nga said she loved those sunflowers
Tom said he couldn't help her to do that test
They said they were doing the exercise then
Daisy's father said he would give her a new bike
They said it was raining so they couldn't go out for a walk
Tom said he had to leave then
She said she wouldn't buy that car because it was very old