=> 1259 - 3x = 275

=> 3x = 984

=> x = 328

(1259-3x):5=55

1259-3x=275

3x=1259-275

3x=984

x=328

( 1259 - y x 3 ) : 5 = 55

1259 - y x 3         = 55 x 5

1259 - y x 3         = 275

          y x 3         = 1259 - 275 

          y x 3         = 984

          y              = 984 : 3

         y               = 328

vậy y = 328

tick nha bạn

( x + 1259 ) x 5 = 67845

( x + 1259 )      = 67845 : 5

( x + 1259 )      = 13569

x                       = 13569 - 1259

x                       = 12310

Mình nghĩ đề bài sai bạn ạ

tk nhé

ai k mình mình k lại

(x+1259)x5=12345+45691

(x+1259)x5=58036

x+1259      =58036:5

x+1259      =11607,2

               x=11607,2-1259

               x=10348,2

\(a.\left(35-815\right)-\left(795-65\right)\\ =35-815-795+65\\ =\left(35+65\right)-\left(815+795\right)\\ =100-1610=-1510\)

Bài 2: 

a: Ta có: \(\left(35-815\right)-\left(795-65\right)\)

\(=35-815-795+65\)

\(=100-1600\)

=-1500

b: Ta có: \(5-197-2015-2015\)

\(=-2010-2212\)

=-4222

c: Ta có: \(1259-1409-12+1259+1409\)

\(=2518-12\)

=2506

1259 + x = 3457

x = 3457 - 1259

x = 2198   

x=3457-1259

x=2198

3457 -1259 = 2198

12 + 34 + 56 + 78 + 123 + 99 + 322 + 199 = 1223

12 x 45 x 67 x 89 x 0 = 0

12 : 4 : 3 x 9 : 3 x 1259 = 3777

Tk nha

  x+125+159=1259

=>  x=1259-159-125

 =>x=975 

= 975

   **** cho tớ nhé bạn tốt !

X + 125 + 159 = 1259

X + 125 = 1259 - 159 

X + 125 = 1100

         X  = 1100 - 125

         X  = 975

`#qlv`

`(11)/(25) . (y + y5 - (23)/(55)) + 3/(14) . (56)/(25) = 1`

`=> (11)/(25) . (6y - (23)/(55)) + (12)/(25) = 1`

`=> (11)/(25) . (6y - (24)/(55)) = 1 - (12)/(25)`

`=> (11)/(25) (6y - (23)/(55)) = (13)/(25)`

`=> 6y - (23)/(55) = (13)/(25) : (11)/(25)`

`=> 6y - (23)/(55) = (13)/(11)`

`=> 6y = (13)/(11) + (23)/(55)`

`=> 6y = 8/5`

`=> y = 8/5 : 6`

`=> y = 8/5 . 1/6`

`=> y = 4/(15)`

Vậy `y = 4/(15)`

\(\dfrac{11}{25}\times\left(y+y\times5-\dfrac{23}{55}\right)+\dfrac{3}{14}\times\dfrac{56}{25}=1\)

\(\Rightarrow\dfrac{11}{25}\times\left(10\times y-\dfrac{23}{55}\right)+\dfrac{12}{25}-1=0\)

\(\Rightarrow\dfrac{22}{5}\times y-\dfrac{23}{125}-\dfrac{13}{25}=0\)

\(\Rightarrow\dfrac{22}{5}\times y=\dfrac{88}{125}\)

\(\Rightarrow y=\dfrac{88}{125}:\dfrac{22}{5}\)

\(\Rightarrow y=\dfrac{4}{25}\)

Vậy