a: x=-1/8+3/4=-1/8+6/8=5/8
b: =>3x-3/4=-16/5
=>3x=-49/20
hay x=-49/60
c: =>7/6x+3x+1/3x=1
=>9/2x=1
hay x=2/9
d: =>(2x+1/2)2=1/4
=>2x+1/2=1/2 hoặc 2x+1/2=-1/2
=>2x=0 hoặc 2x=-1
=>x=0 hoặc x=-1/2
a) \(x-\dfrac{3}{4}=\dfrac{-1}{8}\)
\(x=\dfrac{-1}{8}+\dfrac{3}{4}\)
\(x=-\dfrac{1}{8}+\dfrac{6}{8}=\dfrac{5}{8}\)
b) \(\dfrac{-2}{5}:\left(3x-\dfrac{3}{4}\right)=\dfrac{1}{8}\)
\(3x-\dfrac{3}{4}=\dfrac{-2}{5}:\dfrac{1}{8}\)
\(3x-\dfrac{3}{4}=-\dfrac{16}{5}\)
\(3x=-\dfrac{16}{5}+\dfrac{3}{4}\)
\(3x=-\dfrac{49}{20}\)
\(x=-\dfrac{49}{20}:3=-\dfrac{49}{60}\)
c) \(\dfrac{1}{2}x+\dfrac{2}{3}x-1=-3\dfrac{1}{3}x\)
\(\left(\dfrac{1}{2}+\dfrac{2}{3}\right)x-1=-\dfrac{10}{3}x\)
\(\dfrac{7}{6}x-1=-\dfrac{10}{3}x\)
\(\dfrac{7}{6}x-1-\left(-\dfrac{10}{3}x\right)=0\)
\(\left(\dfrac{7}{6}+\dfrac{10}{3}\right)x-1=0\)
\(\dfrac{9}{2}x-1=0\)
\(\dfrac{9}{2}x=1\)
\(x=1:\dfrac{9}{2}=\dfrac{2}{9}\)
d) \(1-\left(2x+\dfrac{1}{2}\right)^2=\dfrac{3}{4}\)
\(\left(2x+\dfrac{1}{2}\right)^2=1-\dfrac{3}{4}\)
\(\left(2x+\dfrac{1}{2}\right)^2=\dfrac{1}{4}\)
`=>`\(\left[{}\begin{matrix}2x+\dfrac{1}{2}=\dfrac{1}{2}\\2x+\dfrac{1}{2}=-\dfrac{1}{2}\end{matrix}\right.\)
\(\left[{}\begin{matrix}2x=0\\2x=-1\end{matrix}\right.\)
`=>x=`\(\left[{}\begin{matrix}0\\-\dfrac{1}{2}\end{matrix}\right.\)
