\(\left|63-x\right|=75\)

\(\Rightarrow\orbr{\begin{cases}63-x=75\\63-x=-75\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x=-12\\x=138\end{cases}}\)

Vậy: \(x\in\left\{-12;138\right\}\)

|63-x|=75

TH1: 63-x=75

              x=63-75

              x= -12

TH2: 63-x=-75

              x=63- (-75)

              x=63+75

              x=138

\(\left(x+5\right)+\left(x-2\right)< 0\)

\(\Rightarrow x+5+x-2< 0\)

\(\Rightarrow2x+3< 0\)

\(\Rightarrow2x< -3\)

\(\Rightarrow x< -\frac{3}{2}\)

Vậy: \(x< -\frac{3}{2}\)

đề là tìm x

= -5/6

Chúc bạn học tốt

1/2+ -2/3

= 3/6 + -4/6

= -5/6

đó giải ra rùi

\(\frac{-8}{12}=\frac{-2}{3}\)

\(\frac{15}{-60}=\frac{-1}{4}\)

\(\frac{-16}{-72}=\frac{2}{9}\)

\(\frac{35}{14.15}=\frac{1}{6}\)

\(\frac{-8}{12}=\frac{-2}{3}\\ \frac{15}{-60}=\frac{-1}{4}\\ \frac{-16}{-72}=\frac{2}{9}\\ \frac{35}{14.15}=\frac{1}{6}\)

\(\left(1+\frac{1}{1.3}\right).\left(1+\frac{1}{2.4}\right).\left(1+\frac{1}{3.5}\right).....\left(1+\frac{1}{2014.2016}\right)\)

\(=\frac{2^2}{1.3}.\frac{3^2}{2.4}.\frac{4^2}{3.5}....\frac{2015^2}{2014.2016}\)

\(=\frac{2.2.3.3.4.4...2015.2015}{1.3.2.4.3.5....2014.2016}\)

\(=\frac{2.3.4....2015}{1.2.3...2014}.\frac{2.3.4...2015}{3.4.5....2016}\)

\(=\frac{2015}{1}.\frac{2}{2016}\)

\(=\frac{2015}{1008}\)

Ta có: \(\frac{x}{y}=3\Leftrightarrow x=3y\)

           \(\frac{x}{y}=3\Leftrightarrow\frac{y}{x}=\frac{1}{3}\)

Thay x=3y, \(\frac{y}{x}=\frac{1}{3}\)vào biểu thức ta được:

A= 3.3y-\(\frac{1}{3}\)+2y=9y+2y-\(\frac{1}{3}\)=11y-\(\frac{1}{3}\)