a, Để hàm số đồng biến

\(\Leftrightarrow\) \(k^2-3>0\)

\(\Leftrightarrow\) \(k^2>3\)

\(\Leftrightarrow\) \(\Leftrightarrow\left[{}\begin{matrix}k>3\\k< -3\end{matrix}\right.\)

b, Để hàm số nghịch biến

\(\Leftrightarrow\) \(k^2-3< 0\)

\(\Leftrightarrow\) \(k^2< 3\)

\(\Leftrightarrow\) \(-3< k< 3\)

#baoquyen

Pho is one of the(1) most popular Vietnamese dishes.What is Pho?Pho is a Vietnamese noodle soup consisting(2) of broth,rice noodles,herbs and meat.There are two basic(3) kinds of Pho and that is Pho Bo (beef noodle soup) and Pho Ga (chicken noodle soup).Pho Bo is beef(4)______that is made by stewing cow bones in a large pot for quite a long(5)time.Pho Ga is quiet similar to Pho Bo.Instead of beef broth,chicken broth is made by(6) stewing chicken bones.The noodle itself made from varieties of rice.The ingredients and toppings many vary a slight bit in the North and the South.Pho is normally eaten for breakfast,(7 moreover many of people eat at lunch ,or(8)at dinner.

C. WRITING
1. Put the words in the correct order to make meaningful sentences.

1. marks/ Hungry Festival/ a/ celebration/ great/ time/ of/ superstition/, /and/ for/ living/ the/ dead/and/ the.

-> Hungry Ghost Festival marks a time of great superstition, celebration and for the living and the dead.

2. The/ believe/ also/ Chinese/ that/ spirits/ purgatory /stuck/ in/ during/ are/ this/ released/ time.

-> The Chinese also believe that spirits stuck in purgatory are released during this time.

3. preparations/ nearly/ Hungry Ghost Festival/ before/ begin/ the/ a/ week/ the/ onset/ festival/ of.

-> Hungry Ghost Festival preparations begin nearly a week before the onset of the festival.

4. laundry/ Chinese/ hanging/ residents/ avoid/ and/ leaving/ outdoors/ outside/ anything.

-> Chinese residents avoid hanging laundry outdoors and leaving anything outside.

5. On/ the/ the/ festival/ 30th night/ of/, the/ the Chinese/ ghosts/ believe/ have/ their fill/ had/ the underworld/ and/ to/ return.

-> On the 30th night of the festival, the Chinese believe the ghosts have had their fill and return to the underworld.

2. Combine two sentences.
1. The bus arrived. We were talking. (when)

-> When the bus arrived, we were talking

2. We missed the bus. We were so late. (because)

-> Because we were so late, we missed the bus.

3. The hare was sleeping. The tortoise was running. (while)

-> While the hare was sleeping, the tortoise was running

4. Tam worked very hard. Her stepmother wasn't satisfied. (although)

-> Although Tam worked very hard, her stepmother wasn’t satisfied

5. The festival costs too much money. We won't celebrate the festival. (if)

-> If the festival costs too much money, we won’t celebrate it

#baoquyen

\(\frac{3}{4}:\frac{2}{5}=\frac{3}{4}x\frac{5}{2}=\frac{3x5}{4x2}=\frac{15}{8}\)

abc = 198 thấy đúng thì tích mk nha

Ngày 1 cày đc 30% diện tích cánh đồng

Ngày 2 cày đc: 40% x (100-30)%= 28% diện tích cánh đồng

Vậy ngày còn lại phải cày hết 100% - 30% - 28%= 42% diện tích cánh đồng

Số thứ nhất là:

(60-18):2=21

Số thứ hai là:

60-21=39

Đáp số:số thứ nhất 21

Số thứ hai 39

1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9

= (1 + 9) + (2 + 8) + (3 + 7) + (4 + 6) + 5

= 10 + 10 + 10 + 10 + 5

= 45

Diện tích hình vuông là :

   10 x 10 = 100 ( m2 )

      Đ/S :100 m2