There is a large... of animals that live in Nairobi National Park A various B varied C variety D vary

There is a large... of animals that live in Nairobi National Park A various B varied C variety D vary

variety

14b

15c

Đáp án: C

1 . There is a large varity of animals that live in Nairobi National Park . 

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\(\sqrt{x^2-2m}+2.\sqrt{x^2-1}=x\ge0\)

đkxd: \(x^2\ge2m,1\)

Ta có: \(\sqrt{x^2-2m}+2.\sqrt{x^2-1}=x< =>\text{​​}\text{​​}\text{​​}2.\sqrt{x^2-1}=x-\sqrt{x^2-2m}\)

=>\(4.\left(x^2-1\right)=\left(x-\sqrt{x^2-2m}\right)^2\)và \(x-\sqrt{x^2-2m}\ge0< =>x\ge\sqrt{x^2-2m}< =>m\ge0\)

<=>\(4x^2-4=x^2-2x.\sqrt{x^2-2m}+x^2-2m\)

<=>\(2x^2+2m-4=-2x.\sqrt{x^2-2m}\)

<=>\(x^2+m-2=-x.\sqrt{x^2-2m}\)

=>\(\left(x^2+m-2\right)^2=\left(-x\sqrt{x^2-2m}\right)^2\)và \(x^2+m-2\ge0\)

<=>\(x^4+2.\left(m-2\right)x^2+\left(m-2\right)^2=x^4-2m.x^2\)

<=>\(\left(4m-4\right)x^2=-\left(m-2\right)^2\)

-xét m=1=>pt<=>0.x^2=-1(vô lí, loại)

-xét m khác 1

=>\(x^2=\frac{-\left(m-2\right)^2}{4m-4}\)

+Với m>1=>\(x^2=\frac{-\left(m-2\right)^2}{4m-4}< 0\)(vô lí, loại)

+Với 0<_m<1=>\(x^2=\frac{-\left(m-2\right)^2}{4m-4}>0< =>\orbr{\begin{cases}x=-\sqrt{\frac{-\left(m-2\right)^2}{4m-4}}\\x=\sqrt{\frac{-\left(m-2\right)^2}{4m-4}}\end{cases}}\)

Theo điều kiện xác định=>x^2>_1,2m và x^2>_2-m

=>\(\hept{\begin{cases}\frac{-\left(m-2\right)^2}{4m-4}\ge1\\\frac{-\left(m-2\right)^2}{4m-4}\ge2m\end{cases}and\frac{-\left(m-2\right)^2}{4m-4}\ge2-m}< =>\hept{\begin{cases}\frac{\left(m-2\right)^2}{4-4m}\ge1\\\frac{\left(m-2\right)^2}{4-4m}\ge2m\end{cases}and\frac{\left(m-2\right)^2}{4-4m}\ge2-m}\)Vì 4-4m>0=>\(\hept{\begin{cases}\left(m-2\right)^2\ge4-4m\\\left(m-2\right)^2\ge2m\left(4-4m\right)\end{cases}and\left(m-2\right)^2\ge\left(4-4m\right)\left(2-m\right)< =>\hept{\begin{cases}m^2\ge0\\\left(3m-2\right)^2\ge0\end{cases}}}\)và 2/3<_m<_2

Do đó để pt có nghiệm thì 2/3<_m<1

Dịch : 1 công viên động vật có sư tử , hổ và ngựa vằn . 15% trong số chúng là sư tử và 3/5 là ngựa vằn . Biết tất cá có 160 con trong công viên . Hỏi có bao nhiêu con sư tử trong đó ?

                Giải :

Sư tử có tất cả số con là :

   160 : 100 x 15 = 24 con

    Đáp số : 24 con

it ___ that the road through the national park will not affect the environment and living habitat of wild animals there

A. has thought B. had been thought C. is thought D. thinks

~~Study Well~~

C.is thought

Đáp án C. is thought nha!

Giups đi tí mình tick cho

VI. Provide the correct form of the words in capital letters to complete the sentences.

26. There is a large ______variety____ of animals that live in Cuc Phuong National Park. (VARY)

27. Artists are ____creative______ people (CREATE).

28. He works as a ____mechanic______ in this factory. (MACHINE)

29. Reading funny stories is an _______enjoyable___ way to relax. (ENJOY) 30. The newspaper is a means of _______communication________ (COMMUNICATE)

Question 26: There is a large variety of animals that live in Cuc Phuong National Park.

Question 27: Artists are creative people.

Question 28: He works as a machinist in this factory.

Question 29: Reading funny stories is an enjoyable way to relax.

Question 30: The newspaper is a means of communication.