nè, Nhi tưởng 65x4 thì dấu "x" phải là nhân mới đúng chứ, nếu là x thì sao giải đc.

 tớ khi nào hỏi lại để rồi đăng lại!!!

420 + 65x4 = ( x + 175) : 5 + 30

420 + 260   = x : 5 + 175 : 5 + 30 

680            =   x : 5 + 35 + 30 

680 - 30      =  x : 5 + 35 

650            =   x : 5 + 35 

650 - 35      = x : 5 

615             = x : 5

615 x 5        = x

3075            = x 

b) ( 32 x 15) : 2 = ( x + 70):14 - 40

        480 : 2      =   x : 14 + 70 : 14 - 40 

           240        =    x : 14 + 5 - 40 

   240 + 40        = x : 14 + 5

     280              = x: 14 + 5 

    280 - 5          = x : 14 

       275            = x : 14 

   275 x 14         = x

       3850           = x

c) x - 4867 = ( 175 x 2050 x 70) : 25 + 23 

    x - 4867 = 25 112 500 : 25 + 23

    x - 4867 = 1004500 + 23

    x - 4867 = 1004523

    x          = 1004523 + 4867

    x           =           1008390

TÌM SỐ LỚN NHẤT CÓ TỔNG BẰNG 123456

\(420+65\times4=\frac{x+175}{5}+30\)

\(\frac{x+175}{5}=420+260-30\)

\(\frac{x+175}{5}=650\)

\(x+175=650\times5\)

\(x+175=3250\)

x = 3250 - 175

x = 3075

a)420+65x4=(x+175):5+30

420+260=(x+175):5+30

680=(x+175):5+30

680-30=(x+175):5

650=(x+175):5

650x5=x+175

3250=x+175

x=3250-175

x=3075

\(\frac{x+140}{x+260}=71+65.4\)

\(\Leftrightarrow\frac{x+140}{x+260}=71+260\)

\(\Leftrightarrow\frac{x+140}{x+260}=331\)

\(\Leftrightarrow x+140=\left(x+260\right)331\)

\(\Leftrightarrow x+140=86060+331x\)

\(\Leftrightarrow x-331x=85920\)

\(\Leftrightarrow x\left(331-1\right)=85920\)

\(\Leftrightarrow x330=85920\)

\(\Leftrightarrow x\approx260,2\)

420 + 65.4 = (x+175) : 5 + 30

=> 420 + 260 = (x + 175) : 5 + 30

=> 680 = (x + 175) : 5 + 30

=> 680 - 30 = (x + 175) : 5

=> 650 = (x + 175) : 5

=> x + 175 = 650 . 5 = 3250.

=> x = 3250 - 175

=> x = 3075.

(32 . 15) : 2 = (x + 70) : 14 - 40

=> 480 : 2 = (x + 70) : 14 - 40

=> 240 = (x + 70) : 14 - 40

=> x + 70 = 240 + 40 = 280

=> x = 280 - 70 = 210

\(420+65.4=\left(x+175\right):5+30\)

\(420+260=\left(x+175\right):5+30\)

\(680-30=\left(x+175\right):5\)

\(650=\left(x+175\right):5\)

\(650.5=x+175\)

\(3250=x+175\)

\(x=3075\)

vay \(x=3075\)

\(\left(32.15\right):2=\left(x+70\right):14-40\)

\(480:2=\left(x+70\right):14-40\)

\(240+40=\left(x+70\right):14\)

\(280=\left(x+70\right):14\)

\(280.14=x+70\)

\(3920=x+70\)

\(3850=x\)

vay \(x=3850\)

420+ 65 x 4=( X+175 ):5+30

420+260     =( X+175) :5+30

680            =(X+175) :5 +30

650            =(X+175 ):5

X+175        =650 x 5

X+175        = 3250

X                =3075

\(\frac{x+140}{x+260}=71+65\times4\)

\(\Rightarrow\frac{x+260-120}{x+260}=331\)

\(\Rightarrow1-\frac{120}{x+260}=331\)

\(\Rightarrow\frac{120}{x+260}=-330\)

\(\Rightarrow x+260=\frac{120}{-330}\)

\(\Rightarrow x+260=\frac{-4}{11}\)

\(\Rightarrow x=\frac{-4}{11}-260=-\frac{4}{11}-\frac{2860}{11}=\frac{-2864}{11}\)

\(\frac{x+140}{x+260}=71+65.4\)

<=> \(\frac{x+140}{x-260}=331\)

<=> \(\frac{x+140}{x-260}=\frac{331x-86060}{x-260}\)

,<=> \(x+140=331x-86060\)

<=> \(-330x=-86200\)

<=> \(x=\frac{8620}{33}\)

Trả lời:

71+65.4=x+140/x+260

x+140/x+260=71+65.4

x+140/x+260=71+260

x+140/x=71

x/x+140/x=71

1+140/x=71

140/x=71-1

140/x=70

x=140/70

x=2

vậy x=2

cậu ơi cái chỗ 71+65x4 là nhân 4 hay là 65 nhân x nhân 4 ạ

là 65 nhân 4 nghe

x = 2 nhé

71+ 65x4 = (x+140) :x + 260

71 + 260 = x:x + 140:x + 260

71 + 260 - 1- 260 = 140x

70 = 140x 

x= 70 : 140

x= 1/2