\(a,\dfrac{-3}{7}-x=\dfrac{8}{9}\\ =>x=-\dfrac{3}{7}-\dfrac{8}{9}\\ =>x=-\dfrac{83}{63}\)
\(b,\left(\dfrac{3}{10}-x\right):\dfrac{2}{5}=\dfrac{3}{5}\\ =>\dfrac{3}{10}-x=\dfrac{3}{5}\text{×}\dfrac{2}{5}=\dfrac{6}{25}\\ =>x=\dfrac{3}{10}-\dfrac{6}{25}=\dfrac{3}{50}\)
a: =>x=-3/7-8/9=-83/63
b: \(\Leftrightarrow\left(\dfrac{3}{10}-x\right)=\dfrac{3}{5}:\dfrac{2}{5}=\dfrac{3}{2}\)
=>x=3/10-3/2=-6/5
c: \(\Leftrightarrow\left(x-\dfrac{1}{2}\right)^2=4\)
=>x-1/2=2 hoặc x-1/2=-2
=>x=5/2 hoặc x=-3/2
d: =>1/8x+1/2=5/2-3/4=10/4-3/4=7/4
=>1/8x=7/4-1/2=5/4
=>x=10
\(a:\dfrac{-3}{7}-x=\dfrac{8}{9}\\ x=\dfrac{-3}{7}-\dfrac{8}{9}\\ x=-\dfrac{83}{63}\\ b:\left(\dfrac{3}{10}-x\right):\dfrac{2}{5}=\dfrac{3}{5}\\ \dfrac{3}{10}-x=\dfrac{3}{5}\cdot\dfrac{2}{5}\\ \dfrac{3}{10}-x=1\\ x=\dfrac{3}{10}-1\\ x=-\dfrac{7}{10}\\ c:\dfrac{1}{36}\cdot\left(x-\dfrac{1}{2}\right)^2=\dfrac{1}{9}\\ \left(x-\dfrac{1}{2}\right)^2=\dfrac{1}{9}:\dfrac{1}{36}\\ \left(x-\dfrac{1}{2}\right)^2=4\\ \left(x-\dfrac{1}{2}\right)^2=2^2;-2^2\\ x-\dfrac{1}{2}=2\\ x=2+\dfrac{1}{2}\\ x=\dfrac{5}{2}\\ x-\dfrac{1}{2}=-2\\ x=-2+\dfrac{1}{2}\\ x=-\dfrac{3}{2}\\ x=\left\{\dfrac{5}{2};-\dfrac{3}{2}\right\}\)
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