\(=5,63-2,75-2,88=2,88-2,88=0\)

=3,35

\(-8,5+16,35-4,5=3,35\)

(-8,5)+(-4,5)+16,35

= -13+ 16,35

= 3,35

Vì bạn ko niết múa hoặc bạn múa gà

Truyền nhân của ắk wỷ lười:)

c: =21+14+15=50

a) 215

b) - 98

c) 50

d) - 52

e) - 7

f) - 30

\(8x+50=2x+30\\ \Rightarrow8x+50-2x-30=0\\ \Rightarrow6x+20=0\\ \Rightarrow6x=-20\\ \Rightarrow x=-\dfrac{10}{3}\)

\(8 x + 50 = 2 x + 30\)

\(⇒8x+50−2x−30=0\)

\(⇒6x+20=0\)

\(⇒6x=−20\)

\(⇒x=-\frac{10}{3}\)

HT

Em ơi đáp án là 32 nhé

lỗi câu hỏi

:((

\(-8.5\left(16.35+83.65\right)=-8.5\times100=-850\)

`(-8,5) . 16,35 - 8,5 . 83,65`

`= 8,5 . (-16,35 - 83,65)`

`= 8,5 . (-100)`

`= -850`

Lưu ý: Sắp hết học kì mà bận vẫn dùng dấu `xx` này là dở rồi nhé

`−8.5 (16.35+83.65) = −8.5×100 =−850`

\(-8,5\cdot16,35-83.65\cdot8,5\)

= \(8,5\cdot\left(-16,35\right)-83,65\cdot8,5\)

\(=8,5\cdot\left(-16,35-83.65\right)\)

\(=8,5\cdot\left(-100\right)\)

`= -850`

=-8,5(16,35+83,65)=-8,5x100=-850

-8,5 . 16,35 - 83,65 . 8,5

=>8,5.(16,35+83,35)=8,5.100=850

a. \(\widehat{DAB}=\widehat{ABC}=\widehat{BCE}=90^0\)

\(\widehat{ABD}=180^0-\widehat{ABC}-\widehat{EBC}=180^0-60^0-\left(180^0-\widehat{BCE}-\widehat{CEB}\right)=180^0-60^0-\left(180^0-60-\widehat{CEB}\right)=\widehat{CEB}\)\(\Rightarrow\)△ABD∼△CEB (g-g).

\(\Rightarrow\dfrac{AD}{CB}=\dfrac{AB}{CE}\Rightarrow AD.CE=CB.AB\Rightarrow AD.CE=a^2\) không đổi

b. \(\widehat{CAD}=\widehat{BAD}+\widehat{BAC}=60^0+60^0=\widehat{BCE}+\widehat{ACB}=\widehat{ACE}\)

 \(\dfrac{AD}{CB}=\dfrac{AB}{CE}\Rightarrow\dfrac{AD}{AC}=\dfrac{AC}{CE}\)

\(\Rightarrow\)△ACD∼△CEA (c-g-c) 

\(\Rightarrow\left\{{}\begin{matrix}\widehat{ACD}=\widehat{CEA}\\\dfrac{CE}{AC}=\dfrac{EA}{CD}\end{matrix}\right.\)

\(\Rightarrow\)△ACK∼△AEC (g-g).

\(\Rightarrow\dfrac{CK}{EC}=\dfrac{AK}{AC}\Rightarrow\dfrac{CE}{AC}=\dfrac{CK}{AK}\)

\(\Rightarrow\dfrac{AE}{CD}=\dfrac{CK}{AK}\Rightarrow AE.AK=CD.CK\)