\(\frac{3}{4}.\frac{12}{7}+x=\frac{5}{2}\)

\(\frac{3.3}{1.7}+x=\frac{5}{2}\)

\(\frac{9}{7}+x=\frac{5}{2}\)

\(x=\frac{5}{2}-\frac{9}{7}\)

\(x=\frac{35}{14}-\frac{18}{14}\)

\(x=\frac{17}{14}\)

\(\frac{3}{4}.\frac{12}{7}+x=\frac{5}{2}\)

\(\frac{9}{7}+x=\frac{5}{2}\)

\(x=\frac{5}{2}-\frac{9}{7}\)

\(x=\frac{17}{14}\)

Vậy x = \(\frac{17}{14}\)

3,57 . x + 2,43 . x = 27 

x . ( 3 , 57 + 2 , 43 ) = 27 

x . 6 = 27 

x = \(\frac{9}{2}\)

Vạy x = \(\frac{9}{2}\)

cha hiu dc dau

a) \(\frac{X}{2}-\frac{11}{5}=\frac{7}{8}\cdot\frac{64}{49}\)

\(\Rightarrow\frac{x}{2}-\frac{11}{5}=\frac{8}{7}\)

\(\Rightarrow\frac{x}{2}=\frac{8}{7}+\frac{11}{5}\)

\(\Rightarrow\frac{x}{2}=\frac{117}{35}\)\(\Rightarrow x=\frac{117}{35}\cdot2=\frac{234}{35}\)

b)\(\frac{x}{5}+\frac{9}{2}=\frac{6}{7}\cdot\frac{36}{49}\)

\(\Rightarrow\frac{x}{5}+\frac{9}{2}=\frac{216}{343}\)

\(\Rightarrow\frac{x}{5}=\frac{216}{343}-\frac{9}{2}=\frac{-2655}{686}\)

\(\Rightarrow x=\frac{-2655}{686}\cdot5=\frac{-13275}{686}\)

        x/2 - 11/5 = 7/8 . 64/49

        x/2 - 11/5 = 8/7

        x/2          =8/7 + 11/5

        x/2          = 117/35

        x             = 2.117/35 ( tính chất phân số bằng nhau)

        x             = 234/35 

       x/5 + 9/2 = 6/7 . 36/49

       x/5 + 9/2 = 216/343

        x/5         = 216/343 - 9/2

        x/5         = -2655/686

        x           = 5.(-2655)/686

        x           = -13275/686 

tui trả lời trước mà ko tk

a, \(\frac{x}{13}=\frac{35}{91}\)

\(\frac{x}{13}=\frac{5}{13}\rightarrow x=5\)

b, Cậu xem lại đb xem có nhầm ko

Nếu đb là \(9+x=13-x\)

\(\rightarrow2x=4\rightarrow x=2\)

c, Cậu cx xem lại đb ik

a, \(3\left(x-1\right)-\left(2x+3\right)=5\)

\(\Rightarrow3x-3-2x-3=5\)

\(\Rightarrow x-6=5\)

\(\Rightarrow x=11\)

b, \(\frac{6}{13}=\frac{x}{7}\)

\(\Rightarrow x=\frac{6}{13}.7\)

\(\Rightarrow x=\frac{42}{13}\)

c, \(|x|=4\)

\(\Rightarrow x=4\)hoặc \(x=-4\)

d,, \(|x-2|+5=10\)

\(Th1:x-2>0\)

\(\Rightarrow x-2+5=10\)

\(\Rightarrow x+3=10\)

\(\Rightarrow x=7\)

\(Th2;x-2< 0\)

\(\Rightarrow2-x+5=10\)

\(\Rightarrow7-x=10\)

\(\Rightarrow x=-3\)

e, \(3|x-1|-6=9\)

\(Th1:x-1>0\)

\(\Rightarrow3\left(x-1\right)-6=9\)

\(\Rightarrow3x-3-6=9\)

\(\Rightarrow3x-9=9\)

\(\Rightarrow3x=18\)

\(\Rightarrow x=6\)

\(Th2:x-1< 0\)

\(\Rightarrow3\left(1-x\right)-6=9\)

\(\Rightarrow3-3x-6=9\)

\(\Rightarrow-3x-3=9\)

\(\Rightarrow-3x=12\)

\(\Rightarrow x=-4\)

3,57x4,1+2,43x4,1

=(3,57+2,43)x4,1

=6x4,1=24,6

Đúng 100% luôn!

`3,57 : 0,25 + 2,43 xx 4  + 4 `

= `3,57 xx 4 + 2,43 xx 4 + 4 xx1`

= `4 xx(3,57 + 2,43 + 1)`

= `4 xx  7`

= `28`

`652,45xx 27,8 - 27,8 xx 552,45`

= `27,8 xx ( 652,45 - 552,45)`

= `27,8 xx  100`

= `2780`

a. 3,57 : 0,25 + 2,43 x 4 + 4

= 3,57 x 4 + 2,43 x 4 x 4 x 1

= 4 x ( 3,57 + 2,43 + 1)

= 4 x 7

= 28

b. 652,45 x 27,8 - 27,8 x 552,45

= 27,8 x ( 652,45 - 552,45)

= 27,8 x 100

= 2780

=> x . ( 2 + 3 + 4 + 5 + 6 ) = x . 9 + 9999

=> x . 20 = x . 9 + 9999

=> x . 11 = 9999 ( cùng bớt x + 9 )

=> x = 9999 : 11

=> 909

  2x + 3x + 4x + 20x + 6x = 9x + 9999

           35x - 9x                = 9999

                 26x                 = 9999

                     x                 = 9999 / 26

Vậy : x = 9999 / 26

X x 2 + X x 3 + X x4 + X x5 + X x 6 = X x 9 + 9999

                            X x (2+3+4+5+6) = X x 9 +9999

                            X x 20                 = X x 9 +9999

                            X x 11 + X x 9      = X x 9 +9999

(bỏ  X x 9)             X x 11                  =           9999

                            X                         =  9999 : 11

                            X                         = 909

\(=4,1\times\left(3,57+2,43\right)+5,4=4,1\times6+5,4=24,6+5,4=30\)