Question

Answer 1

a: \(-\dfrac{3}{4}+x=-\dfrac{1}{2}\)

=>\(x=-\dfrac{1}{2}+\dfrac{3}{4}=-\dfrac{2}{4}+\dfrac{3}{4}=\dfrac{1}{4}\)

b: \(0,75-\left(x-\dfrac{1}{2}\right)=-\dfrac{1}{4}\)

=>\(x-\dfrac{1}{2}=0,75+\dfrac{1}{4}=0,75+0,25=1\)

=>\(x=1+\dfrac{1}{2}=\dfrac{3}{2}\)

c:\(3\dfrac{1}{5}-\left(\dfrac{1}{2}-x\right)=1,6+\dfrac{3}{10}\)

=>\(3,2-\left(0,5-x\right)=1,6+0,3=1,9\)

=>0,5-x=3,2-1,9=1,3

=>x=0,5-1,3=-0,8

d: \(\dfrac{3}{4}+\dfrac{1}{4}:\left(1,5-\dfrac{1}{2}x\right)=-2\dfrac{1}{3}\)

=>\(\dfrac{1}{4}:\left(1,5-\dfrac{1}{2}x\right)=-\dfrac{7}{3}-\dfrac{3}{4}=-\dfrac{28}{12}-\dfrac{9}{12}=-\dfrac{37}{12}\)

=>\(1,5-\dfrac{1}{2}x=\dfrac{1}{4}:\dfrac{-37}{12}=\dfrac{1}{4}\cdot\dfrac{-12}{37}=\dfrac{-3}{37}\)

=>\(\dfrac{1}{2}x=\dfrac{3}{2}+\dfrac{3}{37}=\dfrac{111+6}{74}=\dfrac{117}{74}\)

=>\(x=\dfrac{117}{74}\cdot2=\dfrac{117}{37}\)

Answer 2

a, \(\dfrac{-3}{4}+x=\dfrac{-1}{2}\)
\(x=\dfrac{-1}{2}-\dfrac{-3}{4}\)
\(x=\dfrac{-2}{4}+\dfrac{3}{4}\)
\(x=\dfrac{1}{4}\)
Vậy...
\(b,0,75-\left(x-\dfrac{1}{2}\right)=\dfrac{-1}{4}\)
\(\dfrac{3}{4}-\left(x-\dfrac{1}{2}\right)=\dfrac{-1}{4}\)
\(x-\dfrac{1}{2}=\dfrac{3}{4}-\dfrac{-1}{4}\)
\(x-\dfrac{1}{2}=1\)
\(x=1+\dfrac{1}{2}\)
\(x=\dfrac{3}{2}\)
Vậy....
\(e,3\dfrac{1}{5}-\left(\dfrac{1}{2}-x\right)=1,6+\dfrac{3}{10}\)
\(\dfrac{16}{5}-\left(\dfrac{1}{2}-x\right)=\dfrac{8}{5}+\dfrac{3}{10}\)
\(\dfrac{16}{5}-\left(\dfrac{1}{2}-x\right)=\dfrac{16}{10}+\dfrac{3}{10}\)
\(\dfrac{16}{5}-\left(\dfrac{1}{2}-x\right)=\dfrac{19}{10}\)
\(\dfrac{1}{2}-x=\dfrac{16}{5}-\dfrac{19}{10}\)
\(\dfrac{1}{2}-x=\dfrac{32}{10}-\dfrac{19}{10}\)
\(\dfrac{1}{2}-x=\dfrac{13}{10}\)
\(x=\dfrac{1}{2}-\dfrac{13}{10}\)
\(x=\dfrac{5}{10}-\dfrac{13}{10}\)
\(x=\dfrac{-8}{10}=\dfrac{-4}{5}\)
Vậy....
\(d,\dfrac{3}{4}+\dfrac{1}{4}:\left(1,5-\dfrac{1}{2}x\right)=-2\dfrac{1}{3}\)
\(\dfrac{3}{4}+\dfrac{1}{4}:\left(\dfrac{3}{2}-\dfrac{1}{2}x\right)=-\dfrac{7}{3}\)
\(\dfrac{1}{4}:\left(\dfrac{3}{2}-\dfrac{1}{2}x\right)=\dfrac{-7}{3}-\dfrac{3}{4}\)
\(\dfrac{1}{4}:\left(\dfrac{3}{2}-\dfrac{1}{2}x\right)=\dfrac{-37}{12}\)
\(\dfrac{3}{2}-\dfrac{1}{2}x=\dfrac{1}{4}:\dfrac{-37}{12}\)
\(\dfrac{3}{2}-\dfrac{1}{2}x=\dfrac{1}{4}.\dfrac{-12}{37}\)
\(\dfrac{3}{2}-\dfrac{1}{2}x=\dfrac{1.\left(-3\right)}{1.37}\)
\(\dfrac{3}{2}-\dfrac{1}{2}x=\dfrac{-3}{37}\)
\(\dfrac{1}{2}x=\dfrac{3}{2}-\dfrac{-3}{37}\)
\(\dfrac{1}{2}x=\dfrac{117}{74}\)
\(x=\dfrac{117}{74}:\dfrac{1}{2}\)
\(x=\dfrac{117}{74}.2\)
\(x=\dfrac{117}{37}\)
Vậy....