Coi số tiền mua là 100%. Số tiền bán bằng:

               100% + 20% = 120% (số tiền mua)

Số tiền vốn để mua số hoa quả đó là:

               1800000 : 120% = 1500000 (đồng)

                         Đáp số : 1500000 đồng

1. How much are those postcards?

What is the total _______cost of  those postcards________________?

2. Do you have a cheaper phone card than this?

Is this the ____cheapest  phone you have________________________?

3. It isn't important for you to finish the work today

You don't ___have to / need to finish the work today___________________

Dùng những từ gợi ý sau để viết các câu hoàn chỉnh.

1. Do / want / post / letter your friend?

____=> Do you want to post a letter to your friend ?_____________

2. How / it / cost / post / local letter / Viet Nam?

__=> How much does it cost to post a local letter in Viet Nam ?________

Chọn đáp án đúng nhất.

A farmer ________ the farm

A: does on               B: works in                    C: makes on           D: works on

1. How much are those postcards?

What is the total _______cost of  those postcards________________?

2. Do you have a cheaper phone card than this?

Is this the ____cheapest  phone you have________________________?

3. It isn't important for you to finish the work today

You don't ___have to / need to finish the work today___________________

Dùng những từ gợi ý sau để viết các câu hoàn chỉnh.

1. Do / want / post / letter your friend?

____=> Do you want to pdsst a letter to your friend ?_____________

2. How / it / cost / post / local letter / Viet Nam?

__=> How much does it cost to post a local letter in Viet Nam ?________

Chọn đáp án đúng nhất.

A farmer ________ the farm

A: does on               B: works in                    C: makes on           D: works on

1, Does your brother like (listen ) ......to listen......... to music in his free time ?

Vì đây là sở thích tạm thời

2, I think in the future, more people ( enjoy ) ........will ẹnoy........ going out by bycycles.

3, My father says when he retired, he ( go ) ......will go...... back to his village to do the gardening .

4, We are planting trees around our school now. Our school ( be ) ........is been........ surrounded by a lot of green trees.

5, lan says she loves collecting pens but she ( not / continue ) .........will not continue........... this hobby from next year.

Chu vi hình chữ nhật ABCD là :

( 84 + 28 ) x 2 =224 ( cm )

Diện tích hình thang EBCD là :

( 28 + 84 ) x 28 : 2 = 1568 ( cm2 )

Cạnh MB là :

28 : 2 = 14 ( cm )

Diện tích hình tam giác EBM là :

28 x 14 : 2 = 196 ( cm2 )

Diện tích hình tam giác MCD là :

84 x 14 : 2 =588 ( cm2 )

Diện tích hình tam giác EDM là :

1568 - ( 196+588 ) =  784 ( cm2 )

Đáp số: : a): 224 cm

              b) : 1568 cm2

              c): 784 cm2

x+y=0

x=0

y=0

Đặt biểu thức là A

=> \(2A=1+\frac{1}{2}+\frac{1}{2^2}+.....+\frac{1}{2^{99}}\)

=> \(2A-A=A=\left(1+\frac{1}{2}+\frac{1}{2^2}+.....+\frac{1}{2^{99}}\right)-\left(\frac{1}{2}+\frac{1}{2^2}+....+\frac{1}{2^{100}}\right)\)

\(\Rightarrow A=1-\frac{1}{2^{100}}\)

Ta có

\(ab=\frac{a}{b}\)

\(\Rightarrow b^2=1\)

\(\Rightarrow\left[\begin{array}{nghiempt}b=1\\b=-1\end{array}\right.\)

(+) Với b=1

\(\Rightarrow a+1=a\)

\(\Rightarrow0=1\) ( vô lý )

(+) Với b = -1

\(\Rightarrow a-1=-a\)

\(\Rightarrow a=\frac{1}{2}\)

Vậy b= - 1 và a = 1/2

II. Chọn đáp án đúng

1. Your composition is .................  better them mine

More                                              Much                                                   Very                                                  Too

2. There are ..................................... lessons on Sunday

No                                                                 Not                                         None                                                  Any

3. I am bored ......................  drinking orange juice

With                                             From                                           Of                                              About

4. He lives ................. the sea 

On                                     In                                               At                                     Near

5. You are right. I agree ................................. you completely.

With                                            To                                     On                                                   By