Tìm x ( x + 6/7) . ( |x| – 1/2) = 0 20% x – x + 1/5 = 3/4 24/07/2021 Bởi Eloise Tìm x ( x + 6/7) . ( |x| – 1/2) = 0 20% x – x + 1/5 = 3/4
`(x + 6/7) . (|x| – 1/2) = 0` `=>` \(\left[ \begin{array}{l}x + \dfrac{6}{7} = 0\\|x| – \dfrac{1}{2} = 0\end{array} \right.\) `=>` \(\left[ \begin{array}{l}x = \dfrac{-6}{7}\\|x| = \dfrac{1}{2}\end{array} \right.\) `=> x ∈ {(-6)/7 ; 1/2 ; (-1)/2}` `20% x – x + 1/5 = 3/4` `=> 1/5 . x – x + 1/5 = 3/4` `=> x . (1/5 – 1) = 3/4 – 1/5` `=> x . (-4)/5 = 11/20` `=> x = 11/20 : (-4)/5` `=> x = 11/20 . (-5)/4` `=> x = (-11)/16` Bình luận
`(x + 6/7) . (|x| – 1/2) = 0`
`=>` \(\left[ \begin{array}{l}x + \dfrac{6}{7} = 0\\|x| – \dfrac{1}{2} = 0\end{array} \right.\)
`=>` \(\left[ \begin{array}{l}x = \dfrac{-6}{7}\\|x| = \dfrac{1}{2}\end{array} \right.\)
`=> x ∈ {(-6)/7 ; 1/2 ; (-1)/2}`
`20% x – x + 1/5 = 3/4`
`=> 1/5 . x – x + 1/5 = 3/4`
`=> x . (1/5 – 1) = 3/4 – 1/5`
`=> x . (-4)/5 = 11/20`
`=> x = 11/20 : (-4)/5`
`=> x = 11/20 . (-5)/4`
`=> x = (-11)/16`
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