Lời giải:
$BC\parallel AD$ nên $\widehat{C}+\widehat{D}=180^0$ (hai góc trong cùng phía)

$\Rightarrow \widehat{D}=180^0-\widehat{C}=180^0-73^0=107^0$

Vì $AB\parallel CD$ nên $\widehat{B}+\widehat{C}=180^0$ (trong cùng phía)

$\Rightarrow \widehat{B}=180^0-\widehat{C}=180^0-73^0=107^0$

$\widehat{A}+\widehat{D}=180^0$ (trong cùng phía)

$\Rightarrow \widehat{A}=180^0-\widehat{D}=180^0-107^0=73^0$

Bài 3: Không có ký hiệu góc. Bạn cần bổ sung thêm

Bài 4:

Vì $AB\parallel CD$ nên:

$\widehat{ACD}+\widehat{BAC}=180^0$ (hai góc trong cùng phía)

$\widehat{ACD}=180^0-\widehat{BAC}=180^0-40^0=140^0$

b.

$AB\parallel CD$ nên:

$\widehat{ACH}=\widehat{CAB}=40^0$ (so le trong)

$CD\parallel EG$ nên:

$\widehat{HCE}=\widehat{CEG}=50^0$ (so le trong)

$\Rightarrow \widehat{ACH}+\widehat{HCE}=40^0+50^0$

Hay $\widehat{ACE}=90^0$

Bài 3: Không có ký hiệu góc. Bạn cần bổ sung thêm

Bài 4:

Vì $AB\parallel CD$ nên:

$\widehat{ACD}+\widehat{BAC}=180^0$ (hai góc trong cùng phía)

$\widehat{ACD}=180^0-\widehat{BAC}=180^0-40^0=140^0$

b.

$AB\parallel CD$ nên:

$\widehat{ACH}=\widehat{CAB}=40^0$ (so le trong)

$CD\parallel EG$ nên:

$\widehat{HCE}=\widehat{CEG}=50^0$ (so le trong)

$\Rightarrow \widehat{ACH}+\widehat{HCE}=40^0+50^0$

Hay $\widehat{ACE}=90^0$

b: B>0

=>\(\dfrac{1}{-x+\sqrt{x}}>0\)

=>\(-x+\sqrt{x}>0\)

=>\(x-\sqrt{x}< 0\)

=>\(\sqrt{x}\left(\sqrt{x}-1\right)< 0\)

=>\(\sqrt{x}-1< 0\)

=>\(\sqrt{x}< 1\)

=>0<=x<1

Kết hợp ĐKXĐ, ta được: 0<x<1

ngu

x+36=120

     x=120-36

     x=84

265+x=321

        x=321-265

        x=56

321+654=975

36+x=587

       x=587-36

       x=551

k nhoa pạn

Arigato :)

I am in Hanoi. I really like going to the Temple of Literature - Quoc Tu Giam because every time I go there, I learn many interesting things about this place. As far as I know, in 1070, Emperor Ly Thanh Tong built the Temple of Literature to worship Confucius. In 1075, Emperor Ly Nhan Tong built a royal academy to teach his children in the court. Chu Van An can be said to be the best teacher ever at the Royal Academy. During the reign of Emperor Le Thanh Tong, he built the first doctorate steles on each stone turtle. That's what I know about the origin of the Temple of Literature - Quoc Tu Giam