Was

Was

= khi phương trình có 2 vế là 1 đẳng thức hoặc bất đẳng thức => khi phương trình có 1 vế là 1 biểu thức

1. This is the man whom I met him in Paris.
2. Ann, who lives next door, is very friendly.
3. That’s the man who he is going to buy the company.
4. Students their homework is late will be punished.
5. We threw out the computer which never worked properly.
6. I’m going to see Sheila ,whom I told you about  yesterday.
7. A man who told me you were away answered the phone.
8. Peter ,whom everyone suspected ,turned out to be innocent.
9. There are some words which they are very difficult to translate.
10. The machine which worked better than the others cost the least.
11. The man whom you met at the party last night is a famous actor.
12. Mary, who looked angry,had been listening to the conversation.
13. James Watt , who was a Scottish scientist,invented the steam engine.
14. She who has just signed a contract with a recording company is a singer.
15. The sun ,which it is one of millions of stars in the universe,provides us with heat and light. 

Xét tam giác ABC có:

 góc A + góc B + góc C= 180 độ ( định lí tổng 3 góc trong 1 tam giác)

<=>45 độ + 45 độ + góc A = 180 độ

=> góc A = 90 độ

=> tam giác ABC vuông tại A

 Mà góc B= góc C(=45 độ)

=> tam giác ABC vuông cân tại A

Xét tam giác ABC vuông cân tại A có:

 \(AB^2+AC^2=BC^2\)

<=>\(2AB^2=BC^2\)

<=>\(2.10^2=BC^2\)

<=>\(BC=10\sqrt{2}\)cm

a)P xác định \(< =>\left\{{}\begin{matrix}x\ne0\\x^2\ne9\\x+1\ne0\end{matrix}\right.< =>\left\{{}\begin{matrix}x\ne0\\x\ne\pm3\\x\ne-1\end{matrix}\right.\)

b)Với \(x\ne0,x\ne\pm3,x\ne-1\)

P=\(\dfrac{\left(2x^2+2x\right)\left(x-3\right)^2}{x\left(x^2-9\right)\left(x+1\right)}=\dfrac{2x\left(x+1\right)\left(x-3\right)^2}{x\left(x+3\right)\left(x-3\right)\left(x+1\right)}=\dfrac{2\left(x-3\right)}{x+3}\)

Ta có:\(x=\dfrac{1}{2}\left(TM\right)\)

Thay \(x=\dfrac{1}{2}\) vào pt P đã rút gọn ta được:

 P=\(\dfrac{2\left(\dfrac{1}{2}-3\right)}{\dfrac{1}{2}+3}=\dfrac{2.\dfrac{-5}{2}}{\dfrac{7}{2}}=-5.\dfrac{2}{7}=\dfrac{-10}{7}\)

c)Với \(x\ne0,x\ne\pm3,x\ne-1\)

P=0<=>\(\dfrac{2\left(x-3\right)}{x+3}=0\)

      <=>2(x-3)=0(Vì \(x\ne-3\))

      <=>x-3=0

       <=>x=3(Không thỏa mãn)

Ta có: Sxq=2xhx(a+b)=420

             <=>2x7(a+b)=420

              =>a+b=30 

hay chu vi là 2(a+b)=2x30=60

1.was

2.was

3.was

4.was

5.Were

6.was

7.was/were

8.was

9.wasn't

10.Were

\(\dfrac{-1}{42}+\dfrac{3}{48}=\dfrac{-1}{42}+\dfrac{1}{16}=\dfrac{-8}{336}+\dfrac{21}{336}=\dfrac{13}{336}\)

21.B->was

22.C-> to vist

23.C->opening

24.D->widened

15.C->had

\(\dfrac{-18}{24}+\dfrac{-15}{21}=\dfrac{-3}{4}+\dfrac{-5}{7}=\dfrac{-21-20}{28}=\dfrac{-41}{28}\)