a) \(\sqrt{13^2-12^2}\)=\(\sqrt{\left(13-12\right)\left(13+12\right)}\)=\(\sqrt{1x25}\)=5

Câu a: Ta có:

√132−122=√(13+12)(13−12)132−122=(13+12)(13−12)

                      =√25.1=√25=25.1=25

                      =√52=|5|=5=52=|5|=5.

Câu b: Ta có:

√172−82=√(17+8)(17−8)172−82=(17+8)(17−8)

                    =√25.9=√25.√9=25.9=25.9

                    =√52.√32=|5|.|3|=52.32=|5|.|3|.

                    =5.3=15=5.3=15.

Câu c: Ta có:

√1172−1082=√(117−108)(117+108)1172−1082=(117−108)(117+108)

                          =√9.225=9.225 =√9.√225=9.225

                          =√32.√152=|3|.|15|=32.152=|3|.|15|

                          =3.15=45=3.15=45.

Câu d: Ta có:

√3132−3122=√(313−312)(313+312)3132−3122=(313−312)(313+312)

                          =√1.625=√625=1.625=625

                          =√252=|25|=25=252=|25|=25.

1. The conversation takes place on the school's 60th anniversary.

2. Our grandparents used to live in an extended family.

3. Because it explains a lot about how the school was in the past.

4.  The roof was made of tiles and some tiles were broken. The window frames were made of wood and some of them were missing

5. They can learn that they are lucky to have such great learning facilities nowadays.

6. My mother is a sympathe woman. She always cares about how we feel.

7. The boys are willing to do what you want the to. They are really obedient.

8.  Having students work in groups, she hoped they could learn to be cooperative.

9.  She is tolerant with her children even when the misbehave.

10. Nowadays the nuclear family is becoming more commor in the cities

* Theo em thì các câu hỏi thuộc chủ đề .. không nên post vì đã có hướng dẫn giải rồi, members sẽ cop và trả lời lại

Write complete sentences, using the words/ phrases given in their correct forms. You can add some more necessary words, but you have to use all the words given.

1. The conversation / take / place / the school's 60th anniversary.

=>  The conversation is taken place on the school's 60th anniversary.

2. Our grandparents / use / live in an extended family.

=>  Our grandparents used to live in an extended family.

3. Because / it explain / a lot about how the school / in the past.

=> . Because it explains a lot about how the school was in the past.

4. The roof / made of tiles / some tiles were broken. / The window frames / made of wood / some of them were missing.\

=> The roof was made of tiles and some tiles were broken. The window frames were made of wood and some of them were missing.

5. They / learn that they / lucky / have / such great learning facilities / nowadays.

=>  They can learn that they are lucky to have such great learning facilities nowadays.

6. My mother / a sympathe woman. / She always care / how / we feel.

=>My mother is a sympathe woman. She always cares about how we feel.

7. The boys / willing to do / what you want / to. / They / really obedient.

=> The boys are willing to do what you want them to. They are really obedient.

1. It consists of industries ranging from mining, seafood processing, agriculture, and construction, to tourism, finance, industry, and trade.

2. The service sector accounts for 51.1%.

3. It’s in District 12.

4. There were three export processing zones and twelve industrial parks.

5. It was opened in 2001.

* Trong gợi ý trả lời có rồi nên mình làm thay đổi một chút, Mong Admin không cop cả câu trả lời để tránh xảy ra Trường hợp chép lại @Sơn :((

1. What does the economy of Ho Chi Minh City consist of?

=> Ho Chi Minh City consists of industries ranging from mining, seafood processing, agriculture, and construction, to tourism, finance, industry, and trade

2. How many percent does the service sector account for in the economic structure?

=>  the service sector accounts for 51.1%.  in the economic structure

3. Where is Quang Trung Software Park?

=>Quang Trung Software Park is in District 12.

4. How many export processing zones and industrial parks were there in the city in 2006?

=> There were three export processing zones and twelve industrial parks in the city in 2006

5. When was the first stock exchange opened?

=> the first stock exchange was opened in 2001.

câu 1

\(\frac{y^2z^2}{x\left(y^2+z^2\right)}=\frac{1}{x}.\left(\frac{y^2z^2}{y^2+z^2}\right)=\frac{1}{x}:\frac{y^2+z^2}{y^2z^2}=\frac{1}{x}:\left(\frac{1}{y^2}+\frac{1}{z^2}\right)\)

tương tự rồi gọi ẩn

câu hình là ở trong đề thi hsg 9 tỉnh đắk lắk năm nay luôn nè :)) 

Khai phương tích 12.30.40 được:

(A) 1200 ;           (B) 120 ;            (C) 12 ;             (D) 240.

Chọn B

Khai phương tích 12.30.40 (=12.12.10.10) ta được 12.10= 120 (Chọn B)

a, \(\sqrt{\frac{2a}{3}}.\sqrt{\frac{3a}{8}}=\sqrt{\frac{6a^2}{24}}=\sqrt{\frac{a^2}{4}}=\left|\frac{a}{2}\right|=\frac{a}{2}\)

do \(a\ge0\)

b, \(\sqrt{13a}.\sqrt{\frac{52}{a}}=\sqrt{\frac{676a}{a}}=\sqrt{676}=26\)

c, \(\sqrt{5a}.\sqrt{45a}-3a=\sqrt{225a^2}-3a=\left|15a\right|-3a\)

\(=15a-3a=12a\)do a > 0 

d, \(=\left(3-a\right)^2-\sqrt{0,2}.\sqrt{180a^2}\)

\(=\left(3-a\right)^2-\sqrt{36a^2}=\left(3-a\right)^2-\left|6a\right|\)

Với \(a\ge0\Rightarrow\left(3-a\right)^2-6a=a^2-6a+9-6a=a^2-12a+9\)

Với \(a< 0\Rightarrow\left(3-a\right)^2+6a=a^2-6a+9+6a=a^2+9\)

a) Ta có:

b) Ta có:

c) Do a ≥ 0 nên bài toán luôn xác định. Ta có:

 

 

d) Ta có:

Bạn học tốt nhé

a)0,6.a

b)\(a^2\).(a-3)

c)36.(a-1)

d)\(\dfrac{1.a^2}{a-b}\).(a-b)

Học tốt nhé :)

a)\(\sqrt{7.63}\)=21

b)\(\sqrt{2,5.30.48}\)=60

c)\(\sqrt{0,4.6,4}\)=1,6

d)\(\sqrt{2,7.5.1,5}\)=4,5

a, \(\sqrt{0.09\cdot64=\sqrt{0.09}\cdot\sqrt{64}=0.3\cdot8=2.4}\)

b, \(\sqrt{2^4\cdot\left(-7\right)^2}=\sqrt{16\cdot49}=\sqrt{16}\cdot\sqrt{49}=4\cdot7=28\)

c, \(\sqrt{121\cdot360}=\sqrt{121\cdot36}=\sqrt{121}\cdot\sqrt{36}=11\cdot6=66\)

d, \(\sqrt{2^2\cdot3^4}=\sqrt{2^2}\cdot\sqrt{3^4}=2\cdot3^2=18\)

a)\(\sqrt{0,09}.\sqrt{64}\)=0,3.8=2,4

b)\(\sqrt{2^4}.\sqrt{\left(-7\right)^2}\)=4.7=28

c)\(\sqrt{121.36}\)=\(\sqrt{121}.\sqrt{36}\)=11.6=66

d)\(\sqrt{2^2}.\sqrt{3^4}\)=2.9=18