x=9867655-456788

x=9410867

x=9886+23345

x=33231

x=986352-283476

x=702876

a: =>136,5-x=6,48

=>x=130,02

b: =>259,2:x=43,2

=>x=6

a/ 136,5 –x = 5 ,4 x 1,2               

    136,5 - x = 6,48

                x = 136,5 - 6,48

                x = 130,02

b/ 259,2 : x = 39 + 4,2    

    259,2 : x = 43,2

                x = 259,2 : 43,2

                x = 6

\(a,243\times x=76545\\ \Rightarrow x=76545:243\\ \Rightarrow x=315\\ b,97328:x=316\\ \Rightarrow x=97328:316\\ \Rightarrow x=308\)

uh 

mt của bạn đâu 

a ) = 315

b ) = 308

\(a.4,75+x=2,4\times5,6\)

\(4,75+x=13,44\)

\(x=13,44-4,75\)

\(x=8,69\)

\(c.x\times7,5=44,625:1,7\)

\(x\times7,5=26,25\)

\(x=26,25:7,5\)

\(x=3,5\)

\(b.x-7,3=13,8+9,37\)

\(x-7,3=23,17\)

\(x=23,17+7,3\)

\(x=30,47\)

\(d.x:6,4=34,7-23,85\)

\(x:6,4=10,85\)

\(x=10,85\times6,4\)

\(x=69,44\)

Bài 6.Tìm x:

a) 4,75 + x = 2,4 x 5,6;     
    4,75 + x = 13,44
               x = 13,44 - 4,75
               x   =   8,69   
b) x – 7,3 = 13,8 + 9,37;     
    x – 7,3 = 23,17
    x          = 23,17 + 7,3
    x          = 30,47
c) x x 7,5 = 44,625 : 1,7;     
    x x 7,5 = 26,25
    x          = 26,25 : 7,5
    x          =  3,5
d) x : 6,4 = 34,7 – 23,85
    x : 6,4  = 10,85
    x          = 10,85 x 6,4
    x          = 69,44

Bài 6.Tìm x:

a) 4,75 + x = 2,4 x 5,6;     
    4,75 + x = 13,44
               x = 13,44 -  4,75
               x   = 8,69     
b) x – 7,3 = 13,8 + 9,37;     
    x – 7,3 = 23,17
    x          = 23,17 + 7,3
    x          = 30,47
c) x x 7,5 = 44,625 : 1,7;     
    x x 7,5 = 26,25
    x          = 26,25 : 7,5
    x          =  3,5
d) x : 6,4 = 34,7 – 23,85
    x : 6,4 = 10,85
    x          = 10,85 x 6,4
    x          = 69,44

\(a,\Leftrightarrow x^2-6x+9-x^2+4=6\\ \Leftrightarrow-6x=-7\Leftrightarrow x=\dfrac{7}{6}\\ b,\Leftrightarrow x\left(x-12\right)=0\Leftrightarrow\left[{}\begin{matrix}x=0\\x=12\end{matrix}\right.\)

Hi

nhanh

Bài 1: Đặt tính rồi tính:

a)      56,7 + 123 = 179,7           

b)      415 – 23,546 = 391,454              

c)       3,45 x 2,1 = 7,245                   

d)     328,32 : 7,2 = 45,6

Bài 4: 

a) \(\dfrac{4}{3}+\left(1,25-x\right)=2,25\)

\(1,25-x=2,25-\dfrac{4}{3}=\dfrac{9}{4}-\dfrac{4}{3}\)

\(1,25-x=\dfrac{11}{12}\)

\(x=1,25-\dfrac{11}{12}=\dfrac{5}{4}-\dfrac{11}{12}\)

\(x=\dfrac{1}{3}\)

b) \(\dfrac{17}{6}-\left(x-\dfrac{7}{6}\right)=\dfrac{7}{4}\)

\(x-\dfrac{7}{6}=\dfrac{17}{6}-\dfrac{7}{4}=\dfrac{34}{12}-\dfrac{21}{12}\)

\(x-\dfrac{7}{6}=\dfrac{13}{12}\)

\(x=\dfrac{13}{12}+\dfrac{7}{6}=\dfrac{13}{12}+\dfrac{14}{12}\)

\(x=\dfrac{27}{12}=\dfrac{9}{4}\)

c) \(4-\left(2x+1\right)=3-\dfrac{1}{3}=\dfrac{9}{3}-\dfrac{1}{3}\)

\(4-\left(2x+1\right)=\dfrac{8}{3}\)

\(2x+1=\dfrac{8}{3}+4=\dfrac{8}{3}+\dfrac{12}{3}\)

\(2x+1=\dfrac{20}{3}\)

\(2x=\dfrac{20}{3}-1=\dfrac{20}{3}-\dfrac{3}{3}\)

\(2x=\dfrac{17}{3}\)

\(x=\dfrac{17}{3}.\dfrac{1}{2}=\dfrac{17}{6}\)

Bài 15:

a) \(\left(\dfrac{-2}{3}\right)^9:x=\dfrac{-2}{3}\)

\(x=\left(\dfrac{-2}{3}\right)^9:\dfrac{-2}{3}=\left(\dfrac{-2}{3}\right)^{9-1}\)

\(=>x=\left(\dfrac{-2}{3}\right)^8\)

b) \(x:\left(\dfrac{4}{9}\right)^5=\left(\dfrac{4}{9}\right)^4\)

\(x=\left(\dfrac{4}{9}\right)^4.\left(\dfrac{4}{9}\right)^5=\left(\dfrac{4}{9}\right)^{4+5}\)

\(=>x=\left(\dfrac{4}{9}\right)^9\)

c) \(\left(x+4\right)^3=-125\)

\(\left(x+4\right)^3=\left(-5\right)^3\)

\(=>x+4=-5\)

\(x=-5-4\)

\(=>x=-9\)

d) \(\left(10-5x\right)^3=64\)

\(\left(10-5x\right)^3=4^3\)

\(=>10-5x=4\)

\(5x=10-4\)

\(5x=6\)

\(=>x=\dfrac{6}{5}\)

e) \(\left(4x+5\right)^2=81\)

\(\Leftrightarrow\left[{}\begin{matrix}\left(4x+5\right)^2=\left(-9\right)^2\\\left(4x+5\right)^2=9^2\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}4x+5=-9\\4x+5=9\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}4x=-14\\4x=4\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{-14}{4}\\x=1\end{matrix}\right.\)

Bài 16:

a) \(4-1\dfrac{2}{5}-\dfrac{8}{3}\)

\(=4-\dfrac{7}{5}-\dfrac{8}{3}\)

\(=\dfrac{60-21-40}{15}=\dfrac{-1}{15}\)

b) \(-0,6-\dfrac{-4}{9}-\dfrac{16}{15}\)

\(=\dfrac{-3}{5}+\dfrac{4}{9}-\dfrac{16}{15}\)

\(=\dfrac{\left(-27\right)+20-48}{45}=\dfrac{-55}{45}=\dfrac{-11}{9}\)

c) \(-\dfrac{15}{4}.\left(\dfrac{-7}{15}\right).\left(-2\dfrac{2}{5}\right)\)

\(=\dfrac{7}{4}.\dfrac{-12}{5}\)

\(=\dfrac{-21}{5}\)

\(#Wendy.Dang\)

Uh, chừa sau k dám học muộn nx

Đăng từng bài `1` thôi cậu ơii

`x+2/5=4/3`

`=>x=4/3-2/5`

`=> x= 20/15 -6/15`

`=>x= 14/15`

__

`x : 3/2 =2 xx 1/5`

`=> x : 3/2= 2/5`

`=> x= 2/5 xx 3/2`

`=> x= 6/10`

`=>x= 3/5`

__

Bài `5` này có `1` chút lạ ạ 

3/5 * x -1/2 = 1/5

giúp mình nhá mình đang cần gấp 

a: x=92,75:25=3,71

b: =>x-5,767=186,8

=>x=192,567

a, 92,75 : x = 25 

               x = 92,75 : 25

               x = 3,71 .

b, x - 5,767 = 200 - 13,2

    x - 5,767 = 186,8

    x             = 186,8 + 5,767

    x             = 192,567 .