Tìm x biết:
(1/5-3/2*x)^2=9/4
( \(\dfrac{1}{5}-\dfrac{3}{2}\cdot x\)) \(^2\)= \(\sqrt{\dfrac{9}{4}}\)
( \(\dfrac{1}{5}-\dfrac{3}{2}\cdot x\)) = \(\dfrac{3}{2}\)
(\(\dfrac{1}{5}-\dfrac{3}{2}\cdot x\)) = \(\pm\dfrac{3}{2}\)
TH 1 :
(\(\dfrac{1}{5}-\dfrac{3}{2}\cdot x\)) = \(\dfrac{3}{2}\)
\(\dfrac{3}{2}\cdot x=\dfrac{1}{5}-\dfrac{3}{2}\)
\(\dfrac{3}{2}\cdot x=\dfrac{-13}{10}\)
x = \(\dfrac{-13}{10}:\dfrac{3}{2}\)
x = \(\dfrac{-12}{15}\)
TH 2:
(\(\dfrac{1}{5}-\dfrac{3}{2}\cdot x\)) = - \(\dfrac{3}{2}\)
\(\dfrac{3}{2}\cdot x=\dfrac{1}{5}+\dfrac{3}{2}\)
\(\dfrac{3}{2}\cdot x=\dfrac{17}{10}\)
x = \(\dfrac{17}{10}:\dfrac{3}{2}\)
x = \(\dfrac{17}{15}\)