a)13-2(x+1)=7

  2.(x+1)=13-7

  2.(x+1)=6

  x+1=6/2

  x+1=3 

  x=3-1

  x=2

a, 13 - 2 ( x + 1 ) = 7

          2 .( x + 1 ) = 13 - 7
          2 .( x + 1 ) = 6
                x + 1   = 6 : 2
                x + 1    = 3
                x          = 3 - 1
                x           = 4

b)6x+2.4=5².2

6x+2=50

6x=48

x=8

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

(x+175):5+30=680

(x+175):5=650

x+175=3250

x=3075

\(1) 420+65.4=(x+175):5+30\)

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

\(\implies 680=(x+175):5+30\)

\(\implies 650=(x+175):5\)

\(\implies 650.5-175=x\)

\(\implies 3075=x\)

\(2)x-4867=(175.2050.70):25+23\)

\(\implies x-4867=1004500+23\)

\(\implies x-4867=1004523\)

\(\implies x=1009390\)

\(3) 134-[(96-7x):4-2]=126\)

\(\implies (96-7x):4-2=8\)

\(\implies(96-7x):4=10\)

\(\implies 96-7x=40\)

\(\implies 7x=56\)

\(\implies x=8\)

\(4) 4-\{100-[(100-5x):8-5]:10\}:25=0\)

\(\implies 4-\{100-[(100-5x):8-5]:10\}=0\)

\(\implies 100-[(100-5x):8-5]:10=4\)

\(\implies 100-[(100-5x):8-5]=40\)

\(\implies (100-5x):8-5=60\)

\(\implies (100-5x):8=65\)

\(\implies 100-5x=520\)

\(\implies 5x=-420\)

\(\implies x=-84\)

~ Hok tốt a~

ai nua cac ban

ban nao biet thi minh h

420 + 65 . 4 = ( x + 175 ) : 5 + 30 

=> ( x + 175 ) : 5 + 30 = 420 + 45 . 4 

=> ( x + 175 ) : 5 + 30 = 600 

=> ( x + 175 ) : 5 = 600 - 30 

=> ( x + 175 ) : 5 = 570 

=> x + 175 = 570 . 5 

=> x + 175 = 2850 

=> x = 2850 - 175 

=> x = 2675 

nha bn 

các câu khác tương tự nhé 

nhớ ủng hộ mik nha mn 

\(\text{Tìm x hở e????}\)

~~~~~~~~~

\(\text{420 + 65 . 4 = ( x + 175 ) : 5 + 30}\)

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

\(680=\text{ ( x + 175 ) : 5 + 30}\)

\(\text{ ( x + 175 ) : 5 + 30=680}\)

\(\text{ ( x + 175 ) : 5 =680-30}\)

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

\(x+175=650:5\)

\(x+175=130\)

\(x=130-175\)

\(x=-45\)

\(\text{(32.15) : 2 = (x + 70) : 14 - 40}\)

\(480:2=\text{ (x + 70) : 14 - 40}\)

\(240\text{ = (x + 70) : 14 - 40}\)

\(\text{ (x + 70) : 14 =280}\)

\(x+70=3920\)

\(x=3920-70\)

\(x=3850\)

\(\text{x - 4867 = ( 175 . 2050 . 76) + 25 + 23}\)

\(\text{x - 4867 = ( 175 . 2050 . 76) + 48}\)

\(x-4867=27265000+48\)

\(x-4867=27265048\)

\(x=27265048+4867\)

\(x=27260015\)

\(\text{Hok giỏi nhé!~!!}\)

* \(20+65.4=\left(x+75\right):5+30\)

\(\Leftrightarrow20+260-30=\frac{x}{5}+\frac{75}{5}\)

\(\Leftrightarrow20+260-30-\frac{75}{5}=\frac{x}{5}\)

\(\Leftrightarrow235=\frac{x}{5}\Rightarrow x=235.5=1175\)

* \(2248:\left[119-\left(x-6\right)\right]=24\)

\(\Leftrightarrow2248:\left(119-x+6\right)=24\)

\(\Leftrightarrow2248:\left(125-x\right)=24\)

A mình lỡ tay, để mình tính tiếp nhá!

\(\Leftrightarrow125-x=2248:24\Leftrightarrow125-x=\frac{281}{3}\Rightarrow-x=\frac{94}{3}\Rightarrow x=-\frac{94}{3}\)(bài này mình thấy sai sai sao á, nếu mình làm sai thì thông cảm cho mình nhé!

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

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

\(\Leftrightarrow\frac{x}{14}+5=280\Leftrightarrow\frac{x}{14}=275\Rightarrow x=3850\)

* \(x-4867=\left(175.2050.70\right):25+23\)

\(\Leftrightarrow x-4867-23=\left(175:25\right).\left(2050:25\right).\left(70:25\right)\)

\(\Leftrightarrow x-4890=7.82.\frac{14}{5}\)

\(\Leftrightarrow x-4890=\frac{8036}{5}\Rightarrow x=\frac{8036}{5}+4890=\frac{32486}{5}\)(bài này mình thấy hình như cũng có cái gì đó sai sai luôn hihi!)

=24 nha

Rút gọn hết ta được :

a/ 41x - 17 = -21

=> 41x = -4 => x = 4/41

b/ 34x - 17 = 0 

=> 34x = 17

=> x = 17/34 = 1/2

c/ 19x + 56 = 52 

=> 19x = -4

=> x = -4/19

d/ 20x² - 16x - 34 = 10x² + 3x - 34

=> 10x² - 19x = 0

=> x(10x - 19) = 0

=> x = 0 

hoặc 10x - 19 = 0 => 10x = 19 => x = 19/10

Vậy x = 0 ; x = 19/10

Rút gọn hết ta được :

a/ 41x - 17 = -21

=> 41x = -4 => x = 4/41

b/ 34x - 17 = 0

=> 34x = 17

=> x = 17/34 = 1/2

c/ 19x + 56 = 52

=> 19x = -4

=> x = -4/19

d/ 20x 2 - 16x - 34 = 10x 2 + 3x - 34

=> 10x 2 - 19x = 0

=> x(10x - 19) = 0

=> x = 0 hoặc 10x - 19 = 0

=> 10x = 19

=> x = 19/10

Vậy x = 0 ; x = 19/10 

a) ( 6x - 3 ) ( 2x + 4 ) + ( 4x - 1 ) ( 5 - 3x ) = -21

<=> 12x² + 24x - 6x - 12 + 20x - 12x² - 5 + 3x = -21

<=> 41x = -21 + 12 + 5 

<=> 41x = -4

<=> x = -4/41

a, \(420+65:4=\left(x+175\right):5+30\)

\(\Rightarrow\left(x+175\right):5+30=420+16,25\)

\(\Rightarrow\left(x+175\right):5=420+16,25-30=406,25\)

\(\Rightarrow x+175=2031,25\)

\(\Rightarrow x=1856,25\)

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

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

\(\Rightarrow\left(x+70\right):14=240+40=280\)

\(\Rightarrow x+70=3920\Rightarrow x=3850\)

c, \(x-4867=\left(175.2050.70\right):25+23\)

\(\Rightarrow x=39462500:25+23+4867\)

\(\Rightarrow x=1578500+23+4867=1583390\)

Chúc bạn học tốt!!!

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

 a) Ta có : 6x(3x + 5) - 2x(9x - 2) + (17 - x)(x - 1) + x(x - 18) = 0

<=> 18x² + 30x - 18x² + 4x + 17x - 17 - x² + x + x² - 18x = 0

<=> 34x - 17 = 0

<=> 34x = 17

=> x = 2