cả nhà giúp mình nha

Ta có:

 \(\left(1-\frac{1}{2}\right)\left(1-\frac{1}{3}\right)\left(1-\frac{1}{4}\right)...\left(1-\frac{1}{99}\right).\left(1-\frac{1}{100}\right)\)

\(=\frac{1}{2}.\frac{2}{3}.\frac{3}{4}...\frac{98}{99}.\frac{99}{100}\) \(=\frac{1.2.3...98.99}{2.3.4...99.100}=\frac{1}{100}\)

nha

9/4 - ( 2/3 :x + 1/4 ) =1/8

         2/3 : x + 1/4 = 9/4 - 1/8 

         2/3 : x + 1/4 = 17 / 8 

        2/3 : x = 17/8 - 1/4 

        2/3 : x = 15/8 

               x = 15/8 x 2/3 

                x =30/24 =5/4 

Chọn đáp án đúng

4. They asked me what...

The children were doing, are the children doing, were the kitchen children doing, the children are doing

5. You should have a dictionary to..the words you want to know about

Look into,look up,look for,look over

6. If I find the book, I...phone you

Will phone,phone,are phoning, are going to phone

1. We finished our work early

-> Our work is finished early.

2. My friend sold her house last year

-> My friend's house was sold last year.

3. They don't plant rice in that country

-> Rice isn't planted in that country.

4. Miss Jones teaches us English on Monday

-> We are taught English by Miss Jones on Monday.

5. People can find a cure for cancer in the future

-> A cure for cancer can be found in the future.

6. We can't wear jeans at school

-> Jeans can't be worn at school.

7. We make paper from wood

-> Paper is made from wood.

Em nghĩ thế chị ạ. Tại vì 1+4=5 thì ta thấy 1 nhân 4 rồi cộng với 1 thì sẽ bằng 5. 2+5=12 thì sẽ là 2 nhân 5 cộng 2 thì bằng 12. 3+6=21 thì là 3 nhân 6 rồi cộng 3. Cuối cùng 8+11= 92 bởi vì 8 nhân 11 rồi cộng với 4 là số tiếp theo.