Do \(\widehat{A_1}+\widehat{A_2}=180^o\)(2 góc kề bù)

 \(\Rightarrow\widehat{A_1}+60^o=180^o\)

\(\Rightarrow\widehat{A_1}=180^o-60^o=120^o\)

Trong Δ ABC có: \(\widehat{A_1}+\widehat{B}+\widehat{C}=180^o\)(tổng 3 góc trong Δ)

                       \(\Rightarrow120^o+x+2x=180^o\)

                       \(\Rightarrow120^o+3x=180^o\)

                       \(\Rightarrow3x=180^o-120^o=60^o\)

                       \(\Rightarrow x=60^o:3=20^o\)

hòn gạch.

Nghĩ thế kkk

Ta có: \(\left(a+b\right)^2=\left(-1\right)^2\)

        \(\Rightarrow a^2+2ab+b^2=1\)

        \(\Rightarrow a^2+b^2=1-2ab\)

        \(\Rightarrow a^2+b^2=1-2.\left(-6\right)\)

        \(\Rightarrow a^2+b^2=1+12=13\)

P = \(a^3+b^3=\left(a+b\right).\left(a^2-2ab+b^2\right)=\left(-1\right).\left[13-2.\left(-6\right)\right]=\left(-1\right).\left(25\right)=-25\)

Đúng rồi nhen :')

ôk

 1.My father will clean the windows tomorrow .

The windows will be cleaned by my father tomorrow 

2. I will meet you at the airport.

You will be met by me at the airport

3. His friend will process your application next week .

Your application will be processed by his friend next week.

4. Somebody will find your glasses tonight .

Your glasses will be found tonight

5. My sister will bring foodand drink tomorrow .

Foodand will be brought by my sister tomorrow

6. They will help you to do this exercise .

You will be helped to do this exercise

7. Somebody will steal your bicycle if you don’t lock it .

Your bicycle will be stole if you don't lock it

8. Somebody will take your order.

Your order will be taken

9. Lan will write a new book about Covid 19.

A new book about Covid 19 will be writen by Lan

10. They will build a new stadium in the centre of the city.

A new stadium in the centre of the city will be built

\(=\dfrac{48}{56}-\dfrac{21}{56}=\dfrac{27}{56}\)

\(\dfrac{36}{45}-\dfrac{5}{45}=\dfrac{31}{45}\)