a) \(\dfrac{13}{20}+\dfrac{3}{5}+x=\dfrac{5}{6}\)

\(\Rightarrow\dfrac{5}{4}+x=\dfrac{5}{6}\)

\(\Rightarrow x=\dfrac{5}{6}-\dfrac{5}{4}\)

\(\Rightarrow x=\dfrac{-5}{12}\)

b) \(x+\dfrac{1}{3}=\dfrac{2}{5}-\dfrac{-1}{3}\)

\(\Rightarrow x+\dfrac{1}{3}=\dfrac{11}{15}\)

\(\Rightarrow x=\dfrac{11}{15}-\dfrac{1}{3}\)

\(\Rightarrow x=\dfrac{2}{5}\)

c)\(\dfrac{-5}{8}-x=\dfrac{-3}{20}-\dfrac{-1}{6}\)

\(\dfrac{-5}{8}-x=\dfrac{1}{60}\)

\(\Rightarrow x=\dfrac{-5}{8}-\dfrac{1}{60}\)

\(\Rightarrow x=\dfrac{-77}{120}\)

d) \(\dfrac{3}{5}-x=\dfrac{1}{4}+\dfrac{7}{10}\)

\(\Rightarrow\dfrac{3}{5}-x=\dfrac{19}{20}\)

\(\Rightarrow x=\dfrac{3}{5}-\dfrac{19}{20}\)

\(\Rightarrow x=\dfrac{-7}{20}\)

e) \(\dfrac{-3}{7}-x=\dfrac{4}{5}+\dfrac{-2}{3}\)

\(\Rightarrow\dfrac{-3}{7}-x=\dfrac{2}{15}\)

\(\Rightarrow x=\dfrac{-3}{7}-\dfrac{2}{15}\)

\(\Rightarrow x=\dfrac{-59}{105}\)

g) \(\dfrac{-5}{6}-x=\dfrac{7}{12}+\dfrac{-1}{3}\)

\(\Rightarrow\dfrac{-5}{6}-x=\dfrac{1}{4}\)

\(\Rightarrow x=\dfrac{-5}{6}-\dfrac{1}{4}\)

\(\Rightarrow x=\dfrac{-13}{12}\)

(x+1/10).5/6=3-7/6

(x+1/10).5/6=18/6-7/6

(x+1/10).5/6=11/6

x+1/10=11/6:5/6

x+1/10=11/6.6/5

x+1/10=11/5

x        =11/5-1/10

x=22/10-1/10

x=21/10

dấu . là dấu nhân nha

Chúc bạn học tốt

Bạn ơi k đúng để làm j vậy kkk

Đặt A=2/3+2/6+2/12+...+2/768

=2/3(1+1/2+1/4+...+1/256)

Đặt B=1+1/2+1/4+...+1/256

=>2B=2+1+1/2+...+1/128

=>B=2-1/256=511/256

=>\(A=\dfrac{2}{3}\cdot\dfrac{511}{256}=\dfrac{511}{128\cdot3}=\dfrac{511}{384}\)

1D (âm 2 còn lại 1)

2A (âm 1 còn lại 2)

3C (âm 2 còn lại 1)

4C (âm 1 còn lại 2)

5B (âm 2 còn lại 1)

6D (âm 2 còn lại 1)

D

C

C

C

B

D

7...7...7=6

Trl:

7 - 7 : 7 = 6

quá vô lý à nha

Em nên gõ công thức trực quan để đề bài rõ ràng nhé

=(-1+2)-(3+4)-(5+6)-........-(2017+2018)

=1-7-11-........-4035

=-1009

\( \left(5x-2\right)\left(x-3\right)=0\)

\(\left[{}\begin{matrix}5x-2=0\\x-3=0\end{matrix}\right.\)\(\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{2}{5}\\x=3\end{matrix}\right.\)