\(\left(3x-1\dfrac{2}{3}\right)^2-\dfrac{5}{4}=\dfrac{1}{2}\\ \left(3x-\dfrac{5}{3}\right)^2=\dfrac{1}{2}+\dfrac{5}{4}\\ \left(3x-\dfrac{5}{3}\right)^2=\dfrac{7}{4}\\ \Rightarrow\left[{}\begin{matrix}3x-\dfrac{5}{3}=\dfrac{\sqrt{7}}{2}\\3x-\dfrac{5}{3}=\dfrac{-\sqrt{7}}{2}\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}3x=\dfrac{\sqrt{7}}{2}+\dfrac{5}{3}\\3x=\dfrac{-\sqrt{7}}{2}+\dfrac{5}{3}\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}3x=\dfrac{3\sqrt{7}+10}{6}\\3x=\dfrac{-3\sqrt{7}+10}{6}\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=\dfrac{3\sqrt{7}+10}{18}\\x=\dfrac{-3\sqrt{7}+10}{18}\end{matrix}\right.\)
biết:
b./ 
c*./ 
b/ 
c/ 
= 
e/ 
= 
và x + y = 22 f/ 
và 
e) 9x =81 
h) 
và x + y= -21 i) 
và 3x - 2y = -2
và 3x – 2y – z = -29