\(\frac{11}{13}-\left(\frac{5}{42}-x\right)=-\left(\frac{15}{28}-\frac{11}{13}\right)\)

\(=\frac{11}{13}-\left(\frac{5}{42}-x\right)=\frac{113}{364}\)

\(\Rightarrow\frac{5}{42}-x=\frac{11}{13}-\frac{113}{364}\)

\(\Rightarrow x=\frac{5}{42}-\frac{15}{28}\)

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

\(\frac{11}{13}-\left(\frac{5}{42}-x\right)=-\left(\frac{15}{28}-\frac{11}{13}\right)\)

<=> \(\frac{11}{13}-\frac{5}{42}+x=-\left(-\frac{113}{364}\right)\)

<=> \(\frac{397}{546}+x=\frac{113}{364}\)

<=> \(x=\frac{-5}{12}\)

học tốt

a,\(\frac{11}{12}-\left(\frac{5}{42}-x\right)=\frac{15}{28}-\frac{11}{12}\)

\(\Leftrightarrow\frac{11}{12}-\frac{5}{42}+x=\frac{15}{28}-\frac{11}{12}\)

\(\Leftrightarrow x=\frac{15}{28}-\frac{11}{12}-\frac{11}{12}+\frac{5}{42}\)

\(\Leftrightarrow x=\left(\frac{15}{28}+\frac{5}{42}\right)-\left(\frac{11}{12}+\frac{11}{12}\right)\)

\(\Leftrightarrow x=\frac{55}{84}-\frac{11}{6}\)

\(\Leftrightarrow x=\frac{-33}{28}\)

b, \(\frac{x+1}{10}+\frac{x+1}{11}+\frac{x+1}{12}=\frac{x+1}{13}+\frac{x+1}{14}\)

\(\Leftrightarrow\frac{x+1}{10}+\frac{x+1}{11}+\frac{x+1}{12}-\frac{x+1}{13}-\frac{x+1}{14}=0\)

\(\Leftrightarrow\left(x+1\right)\left(\frac{1}{10}+\frac{1}{11}+\frac{1}{12}-\frac{1}{13}-\frac{1}{14}\right)=0\)

\(\Leftrightarrow x+1=0\)

\(\Leftrightarrow x=-1\)

\(\frac{1}{13}-\left(\frac{5}{42}-x\right)=-\left(-\frac{113}{364}\right)\)

=>\(\frac{1}{13}-\frac{5}{42}+x=\frac{113}{364}\)

=>\(-\frac{23}{546}+x=\frac{113}{364}\)

=>\(x=\frac{113}{364}-\left(-\frac{23}{546}\right)\)

=>\(x=\frac{113}{364}+\frac{23}{546}\)

=>\(x=\frac{55}{156}\)

\(\frac{11}{13}-\left(\frac{5}{42}-x\right)=-\left(\frac{15}{28}-\frac{11}{13}\right)\)

\(\frac{11}{13}-\frac{5}{42}+x=-\frac{15}{28}+\frac{11}{13}\)

\(\frac{-5}{42}+x=-\frac{15}{28}+\left(\frac{11}{13}-\frac{11}{13}\right)\)

\(\frac{-5}{42}+x=-\frac{15}{28}\)

\(x=-\frac{15}{28}+\frac{5}{42}\)

\(x=-\frac{45}{84}+\frac{10}{84}\)

\(x=-\frac{35}{84}\)

Vậy \(x=-\frac{35}{84}\).

\(\frac{11}{13}-\left(\frac{5}{42}-x\right)=\frac{113}{364}\)

\(\left(\frac{5}{42}-x\right)=\frac{11}{13}-\frac{113}{364}\)

\(\left(\frac{5}{42}-x\right)=\frac{15}{28}\)

\(x=\frac{5}{42}-\frac{15}{28}\)

\(x=-\frac{5}{12}\)

vậy \(x=-\frac{5}{12}\)

                              Bài làm :

Ta có :

\(\frac{11}{13}-\left(\frac{5}{42}-x\right)=-\left(\frac{15}{28}-\frac{11}{13}\right)\)

\(\Leftrightarrow\frac{11}{13}-\left(\frac{5}{42}-x\right)=\frac{113}{364}\)

\(\Leftrightarrow\frac{5}{42}-x=\frac{11}{13}-\frac{113}{364}\)

\(\Leftrightarrow\frac{5}{42}-x=\frac{15}{28}\)

\(\Leftrightarrow x=\frac{5}{42}-\frac{15}{28}=-\frac{5}{12}\)

Chúc bạn học tốt !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

mọi ng trả lời hộ mik nhé cảm ơn các bn ạk

Đề sai không bạn ?

= (15/28-11/13) ak bn xl mik viết nhầm

1) \(\dfrac{11}{12}\times\dfrac{28}{13}-\dfrac{11}{12}\times\dfrac{15}{13}=\dfrac{11}{12}\times\left(\dfrac{28}{13}-\dfrac{15}{13}\right)=\dfrac{11}{12}\times\dfrac{13}{13}=\dfrac{11}{12}\times1=\dfrac{11}{12}\)

Vậy biểu thức trên có kết quả là : \(\dfrac{11}{12}\)

2) \(x+653=87\times11\)

    \(x+653=957\) 

    \(x=957-653\)

    \(x=304\)

Vậy `x = 304 `

3) \(\text{70 000 + 800 + 20 + 9}=70829\)