giá trị tuyệt đối của 2/5x+1/3/ = (-1/2) mũ2 17/08/2021 Bởi Iris giá trị tuyệt đối của 2/5x+1/3/ = (-1/2) mũ2
`2 . | 5x + 1/3 | = ( – 1 )/2^2` `⇔ 2 . | 5x + 1/3 | = 1/4` `⇔ | 5x + 1/3 | = 1/4 : 2` `⇔ | 5x + 1/3 | = 1/8` `⇔` \(\left[ \begin{array}{l}5x + 1/3 = 1/8\\5x + 1/3 = – 1/8\end{array} \right.\) `⇔` \(\left[ \begin{array}{l}5x = – 5/24\\x = – 11/24\end{array} \right.\) `⇔` \(\left[ \begin{array}{l}x = – 1/24\\x = – 11/120\end{array} \right.\) Vậy , `x ∈ { ( – 1 )/24 ; ( – 11 )/120 }` Bình luận
Đáp án : `x\in{\frac{-5}{24};\frac{-35}{24}}` Giải thích các bược giải `|\frac{2}{5}x+\frac{1}{3}|=(-\frac{1}{2})^2` `|\frac{2}{5}x+\frac{1}{3}|=\frac{1}{4}` `TH1:\frac{2}{5}x+\frac{1}{3}=\frac{1}{4}` `\frac{2}{5}x=\frac{-1}{12}` `x=\frac{-5}{24}` `TH2:\frac{2}{5}x+\frac{1}{3}=-\frac{1}{4}` `\frac{2}{5}x=\frac{-7}{12}` `x=\frac{-7}{12}:\frac{2}{5}` `x=\frac{-35}{24}` Vậy `x\in{ \frac{-35}{24};\frac{-5}{24}}` Bình luận
`2 . | 5x + 1/3 | = ( – 1 )/2^2`
`⇔ 2 . | 5x + 1/3 | = 1/4`
`⇔ | 5x + 1/3 | = 1/4 : 2`
`⇔ | 5x + 1/3 | = 1/8`
`⇔` \(\left[ \begin{array}{l}5x + 1/3 = 1/8\\5x + 1/3 = – 1/8\end{array} \right.\)
`⇔` \(\left[ \begin{array}{l}5x = – 5/24\\x = – 11/24\end{array} \right.\)
`⇔` \(\left[ \begin{array}{l}x = – 1/24\\x = – 11/120\end{array} \right.\)
Vậy , `x ∈ { ( – 1 )/24 ; ( – 11 )/120 }`
Đáp án :
`x\in{\frac{-5}{24};\frac{-35}{24}}`
Giải thích các bược giải
`|\frac{2}{5}x+\frac{1}{3}|=(-\frac{1}{2})^2`
`|\frac{2}{5}x+\frac{1}{3}|=\frac{1}{4}`
`TH1:\frac{2}{5}x+\frac{1}{3}=\frac{1}{4}`
`\frac{2}{5}x=\frac{-1}{12}`
`x=\frac{-5}{24}`
`TH2:\frac{2}{5}x+\frac{1}{3}=-\frac{1}{4}`
`\frac{2}{5}x=\frac{-7}{12}`
`x=\frac{-7}{12}:\frac{2}{5}`
`x=\frac{-35}{24}`
Vậy `x\in{ \frac{-35}{24};\frac{-5}{24}}`