Đáp án:
a) `x=1/2`
b) `x=-1/24`
c) `x=5/4` hoặc `x=7/4`
Giải thích các bước giải:
Câu 8:
a, `2x+1/4=5/4`
`<=> 2x=5/4-1/4`
`<=> 2x=4/4`
`<=> 2x=1`
`<=> x=1/2`
b) `1/2-3x=x+2/3`
`<=> -3x-x=-1/2+2/3`
`<=> -4x=4/6-3/6`
`<=> -4x=1/6`
`<=> x=1/6:(-4)`
`<=> x=-1/24`
c) `|2x-3|=1/2`
`<=>` \(\left[ \begin{array}{l}2x-3=1/2\\2x-3=-1/2\end{array} \right.\)
`<=>` \(\left[ \begin{array}{l}2x=1/2+3\\2x=-1/2+3\end{array} \right.\)
`<=>` \(\left[ \begin{array}{l}2x=7/2\\2x=5/2\end{array} \right.\)
`<=>` \(\left[ \begin{array}{l}x=7/2:2\\x=5/2:2\end{array} \right.\)
`<=>` \(\left[ \begin{array}{l}x=7/4\\x=5/4\end{array} \right.\)
