A, 11/12

B, 12,6

a,

x- 7/12 = 1/3

x = 1/3 + 7/12

x = 11/12

b,

x + 31/10 = 14,5

x = 14,5 - 31/10

x = 57/5

\(a,\\ x=\dfrac{1}{3}+\dfrac{7}{12}=\dfrac{11}{12}\\ b,\\ x+\dfrac{31}{10}=\dfrac{157}{10}\\ x=\dfrac{157}{10}-\dfrac{31}{10}=\dfrac{63}{5}\)

(-23)+(+31)=8

(-37)+65+(-12)+(-1)=15

tim x

-5<x<5

=> x thuộc {-4;-3;-2;-1;0;1;2;3;4;5}

219-7.(x+1)=10

7.(x+1)=219-10

7.(x+1)=209

   x+1=209:7

   x+1=27

   x    =27-1

   x     =26

(3x-6).3=3⁴

(3x-6).3=81

3x-6    =81:3

3x-6   =27

3x      =27+6

3x     =33

 x     =33:3

 x     =11

\(x+\frac{31}{10}=14,5+\frac{12}{10}\)

\(x+\frac{31}{10}=\frac{29}{2}+\frac{12}{10}\)

\(x+\frac{31}{10}=\frac{157}{10}\)

\(x=\frac{157}{10}-\frac{31}{10}\)

\(x=\frac{63}{5}\)

Học tốt #

\(x+\frac{31}{10}=14,5+\frac{12}{10}\)

\(\Rightarrow x+\frac{31}{10}=\frac{157}{10}\)

\(\Rightarrow x=\frac{157}{10}-\frac{31}{10}\)

\(\Rightarrow x=\frac{63}{5}\)

Vậy  \(x=\frac{63}{5}\)

_Chúc bạn học tốt_

x+31/10=14,5+12/10

x+31/10=29/2 + 12 /10

x+31/10=145/10+12/10

x+31/10=157/10

x=157/10-31/10

x=63/5

Vậy x=63/5

\(\frac{63}{5}\)

x+3.1=15.7

x=12.6

tik nha

63/5 duyệt đi

\(x+\frac{31}{10}=x+\frac{12}{10}+\frac{19}{10}=14,5+\frac{12}{10}\)

\(x+\frac{19}{10}=14,5\)

\(x+1,9=14,5\)

\(x=14,5-1,9=12,6\)

x+\(\frac{31}{10}\)=\(\frac{157}{10}\)

x=\(\frac{157}{10}-\frac{31}{10}\)

x=\(\frac{63}{5}\)

a: =>x+6,5=6,48

=>x=-0,02

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

=>x=6

c: =>x*5,3=36,04

=>x=6,8

d: =>67,89-x=13,6

=>x=54,29

10+x/17+x=3/4

<=>x/17+x=10+3/4

<=>x(1/17+1)=43/4

<=>x*18/17=43/4

=>x=43/4:18/17=....

Còn lại bạn tính nhé