Question

lam gium minh voi a

Answer 1

a.\(\dfrac{2x+1}{5}-\dfrac{3+x}{10}=6\)

\(\Leftrightarrow\dfrac{2\left(2x+1\right)-\left(3+x\right)}{10}=\dfrac{60}{10}\)

\(\Leftrightarrow2\left(2x+1\right)-\left(3+x\right)=60\)

\(\Leftrightarrow4x+2-3-x=60\)

\(\Leftrightarrow3x=61\)

\(\Leftrightarrow x=\dfrac{61}{3}\)

Vậy \(S=\left\{\dfrac{61}{3}\right\}\)

Answer 2

b.\(\left|x-2\right|=3x+5\)

\(ĐK:x\ge-\dfrac{5}{3}\)

\(\Leftrightarrow\left[{}\begin{matrix}x-2=3x+5\\2-x=3x+5\end{matrix}\right.\) \(\Leftrightarrow\left\{{}\begin{matrix}x=-\dfrac{7}{2}\left(ktm\right)\\x=-\dfrac{3}{4}\left(tm\right)\end{matrix}\right.\)

Vậy \(S=\left\{-\dfrac{3}{4}\right\}\)

Answer 3

\(\dfrac{2x+1}{5}-\dfrac{3+x}{10}=6\)

\(\Leftrightarrow\dfrac{2\left(2x+1\right)}{10}-\dfrac{3+x}{10}=\dfrac{60}{10}\)

\(\Leftrightarrow4x+2-3-x=60\)

\(\Leftrightarrow3x-1=60\)

\(\Leftrightarrow3x=61\)

\(\Leftrightarrow x=\dfrac{61}{3}\)

Vậy....

\(\left|x-2\right|=3x+5\)

Nếu \(x-2\ge0\) thì \(x\ge2\)

\(\Leftrightarrow x-2=3x+5\)

\(\Leftrightarrow x-3x=5+2\)

\(\Leftrightarrow-2x=7\)

\(\Leftrightarrow x=-\dfrac{7}{2}\) (ktm)

Nếu \(x-2< 0\) thì \(x< 2\) 

\(\Leftrightarrow x-2=-3x-5\)

\(\Leftrightarrow x+3x=-5+2\)

\(\Leftrightarrow4x=-3\)

\(\Leftrightarrow x=-\dfrac{3}{4}\left(tm\right)\)

Vậy.....

 

Answer 4