a/\(-\left(-432-3x\right)+\left(-432-4x+21\right)=-2345\)

\(\Leftrightarrow+432+3x-432-4x+21=-2345\)\(\Leftrightarrow\left[432+\left(-432\right)\right]+\left[\left(-4x\right)+3x\right]+21=-2345\)

\(\Leftrightarrow0+-1x+21=-2345\)\(\Leftrightarrow-1x=-2345-21=-2366\)

\(\Rightarrow x=\left(-2366\right):\left(-1\right)=2366\)

b/\(12x-\left(-3546-3x\right)=\left(2x-234\right)-\left(-678-2x\right)\)

\(\Leftrightarrow12x+3546+3x=2x-234+678+2x\)

\(\Leftrightarrow15x+3546=\left(2x+2x\right)+\left[\left(-234\right)+678\right]\)

\(\Leftrightarrow15x+3546=4x+444\)

\(\Leftrightarrow15x+3546-4x-444=0\)

\(\Leftrightarrow\left(15x-4x\right)+\left(3546-444\right)=0\)

\(\Leftrightarrow11x+3102=0\)

\(\Leftrightarrow11x=0-3102=-3102\)

\(\Rightarrow x=\left(-3102\right):11=-282\)

số đó là 5

Bạn tự đăng, tự trả lời??

Số đó là: \(21132,24324\times555:23456789=0,5...\)

Ta có :

250 * y + 750 * y = 1001 * 2345 - 2345

=> ( 250 + 750 ) * y = ( 1001 - 1 ) * 2345

=> 1000 * y = 1000 * 2345

=> y = 2345

Vậy y = 2345

\(yx\left(250+750\right)=2347345-2345\)

\(yx1000=2345000\)

\(y=2345000:1000\)

\(y=2345\)

y=2345

Đề thiếu z

Ta có: \(\dfrac{1}{10001}=\dfrac{1234}{x}=\dfrac{y}{45674567}=\dfrac{2345}{t}\)

\(\Rightarrow\left\{{}\begin{matrix}x=1234.10001=12341234\\y=\dfrac{45674567}{10001}=4567\\t=2345.10001=23452345\end{matrix}\right.\)

Vì 1/10001 = 1234/x => x = 10001.1234 = 12341234

Vì 1/10001 = y/45674567 => y = y.10001 = 45674567 <=>

y = 4567

Vì 1/10001 = 2345/t => t = 10001.2345 = 23452345

Vậy...

Answer:

\(\frac{1}{10001}=\frac{1234}{x}=\frac{y}{45674567}=\frac{2345}{t}\)

\(\Rightarrow\hept{\begin{cases}x=1234.10001=12341234\\y=45674567:10001=4567\\t=2345.10001=23452345\end{cases}}\)

sao ko ai trả lời zậy

x + ( x + 1 ) + ( x + 2 ) + .... + ( x + 2344 ) + 2345 = 2345

      ( có 2346 số hạng ) 

x + ( x + 1 ) + ( x + 2 ) + ..... + ( x + 2344 ) = 2345 - 2345

x + ( x + 1 ) + ( x + 2 ) + ..... + ( x + 2344 ) = 0

 ( có 2345 số hạng )

[ ( x + 2344 ) + x ] . 2345 : 2 = 0

[ ( x + 2344 ) + x ] . 2345 = 0 . 2

( 2x + 2344 ) . 2345 = 0

2x + 2344 = 0 : 2345

2x + 2344 = 0

2x = 0 - 2344

2x = - 2344

x = - 2344 : 2 = - 1172

Vậy x = - 1172 

Đáp án A

a

chọn  A.11 728

20x23456789=469135780

                    Đáp số : 469135780

469135780