giúp mình với

a. x + 3/10= 25/8

x = 25/8-3/10

x = 113/40

b. x/35 = 4/5-5/7

x/35 = 3/35

vậy x=3

\(x+\dfrac{3}{10}=4-\dfrac{7}{8}\)

\(x+\dfrac{3}{10}=\dfrac{25}{8}\)

        \(x=\dfrac{25}{8}-\dfrac{3}{10}\)

       \(x=\dfrac{113}{40}\)

\(\dfrac{5}{7}+\dfrac{x}{35}=\dfrac{4}{5}\)

        \(\dfrac{x}{35}=\dfrac{4}{5}-\dfrac{5}{7}\)

        \(\dfrac{x}{35}=\dfrac{3}{35}\)

    =>x=3

77/45

7/6

29/10

\(\dfrac{3}{5}+\dfrac{4}{3}\times\dfrac{5}{6}=\dfrac{3}{5}+\dfrac{10}{9}=\dfrac{27}{45}+\dfrac{50}{45}=\dfrac{77}{45}\)

\(2-\dfrac{7}{6}+\dfrac{1}{3}=\dfrac{12}{6}-\dfrac{7}{6}+\dfrac{2}{6}=\dfrac{7}{6}\)

\(\dfrac{7}{6}\times3-\dfrac{3}{5}=\dfrac{7}{2}-\dfrac{3}{5}=\dfrac{35}{10}-\dfrac{6}{10}=\dfrac{29}{10}\)

giải chi tiết đi

a) 

5.(12-x)-20=30

⇒60-5x-20=30

⇒-5x=30+20-60

⇒-5x=-10

⇒x=2

b)(17x - 25 ) : 8 + 65 = 9²

(17x - 25 ) : 8 + 65 = 81

17x - 25 = 16 x 8 = 128

17x = 128+25=153

x= 153:17 =9

c)

x=23

Giải thích các bước giải:

3x – 10 = 2x + 13

3x-2x=13+10

x=23

d)4(2x+7)-3(3x-2)=24

4.2x+4.7-3.3x+3.2=24

8x+28-9x+6=24

8x-9x=24-28-6=-10

=>(-1)x=-10

        x=-10:(-1)

        x=10

a. \(5\cdot\left(12-x\right)-20=30\Leftrightarrow5\left(12-x\right)=50\)

\(\Leftrightarrow12-x=50:5=10\)

\(\Leftrightarrow x=12-10=2\)

b. \(\left(17x-25\right):8+65=9^2\)

\(\Leftrightarrow\left(17x-25\right):8=81-65=16\)

\(\Leftrightarrow17x-25=16:8=2\)

\(\Leftrightarrow17x=2+25=27\Leftrightarrow x=\frac{27}{17}\)

c. \(3x-10=2x+13\)

\(\Leftrightarrow3x-2x=10+13\)

\(\Leftrightarrow x=23\)

d. \(4\cdot\left(2x+7\right)-3\cdot\left(3x-2\right)=24\)

\(\Leftrightarrow8x+28-9x+6=24\)

\(\Leftrightarrow34-x=24\Leftrightarrow x=10\)

a) 

5.(12-x)-20=30

⇒60-5x-20=30

⇒-5x=30+20-60

⇒-5x=-10

⇒x=2

b)(17x - 25 ) : 8 + 65 = 9²

(17x - 25 ) : 8 + 65 = 81

17x - 25 = 16 x 8 = 128

17x = 128+25=153

x= 153:17 =9

c)

x=23

Giải thích các bước giải:

3x – 10 = 2x + 13

3x-2x=13+10

x=23

d)4(2x+7)-3(3x-2)=24

4.2x+4.7-3.3x+3.2=24

8x+28-9x+6=24

8x-9x=24-28-6=-10

=>(-1)x=-10

        x=-10:(-1)

        x=10

1) 11 - x = 8 - ( -11 )

    11 - x = 19

          x = 11 - 19

          x = -8

2) x - 21 = ( -7 ) - 4

    x - 21 = -11

           x = ( -11 ) + 21 

           x = 10

3) 46 - x = -21 + ( -87 )

   46 - x = -108

         x = 46 - ( -108 )

         x = 154

1)11-x=8+11
11-x=19
     x=11-19
     x=-8
2)Mk ko bt
3)46-x=-108
        x=46-(-108)
        x=46+108
        x=154
4) x-96=443-x-15
    x-96=443-15-x
    x-96=428-x
    x+x=428=96
2x+524
x=524:2
x=262
5) Mk ko bt
Mk chỉ bt 3 câu này thui bạn ak

\(\Leftrightarrow\left\{{}\begin{matrix}2x-3>=-5\\2x-3< =5\end{matrix}\right.\Leftrightarrow-1< =x< =4\)

a) \(\dfrac{3}{5}\times x=\dfrac{4}{7}\)

            \(x=\dfrac{4}{7}\div\dfrac{3}{5}\)

            \(x=\dfrac{20}{21}\)

b) \(\dfrac{1}{8}\div x=\dfrac{1}{5}\)

           \(x=\dfrac{1}{8}\div\dfrac{1}{5}\)

          \(x=\dfrac{5}{8}\)

20/21

5/8

20/21

5/8

giúp mình đi mọi người T.T

a) x = 6/5 - 5/6

    x =  11/30

vậy x =...

b) x = 13/4 - 3/5 

    x = 53/20

vậy x =...

a. x=6/5-5/6=11/30

b.13/4-3/5=53/20

a) \(\dfrac{49}{81}=\dfrac{7^x}{9^x}\)(sửa đề)

\(\Leftrightarrow\left(\dfrac{7}{9}\right)^2=\left(\dfrac{7}{9}\right)^x\)\(\Rightarrow x=2\)

b) \(\dfrac{-64}{343}=\left(-\dfrac{4^x}{7^x}\right)\)(sửa đề)

\(\Leftrightarrow\left(-\dfrac{4}{7}\right)^3=\left(-\dfrac{4}{7}\right)^x\) \(\Rightarrow x=3\)

c) \(\dfrac{9}{144}=\dfrac{3^x}{12^x}\)(sửa đề)

\(\Leftrightarrow\left(\dfrac{3}{12}\right)^2=\left(\dfrac{3}{12}\right)^x\Rightarrow x=2\)

d) \(-\dfrac{1}{32}=\left(-\dfrac{1^x}{2^x}\right)\)(sửa đề)

\(\Leftrightarrow\left(-\dfrac{1}{2}\right)^5=\left(-\dfrac{1}{2}\right)^x\Rightarrow x=5\)

Mong bạn xem lại đề bài.

x:5/3=9/5+2/5

x:5/3=11/5

x=11/5.5/3

x=11/3

x : 5/3 = 9/5 - 2/5

x : 5/3 = 7/5

x = 7/5 x 5/3

x = 7/3

\(x:\dfrac{5}{3}+\dfrac{2}{5}=\dfrac{9}{5}\)

\(x:\dfrac{5}{3}=\dfrac{9}{5}-\dfrac{2}{5}\)

\(x:\dfrac{5}{3}=\dfrac{7}{5}\)

\(x=\dfrac{7}{5}\times\dfrac{5}{3}\)

\(x=\dfrac{35}{15}=\dfrac{7}{3}\)