Đáp án:
`a)`
`(2x+1)/5=2 => 2x+1=10 => 2x=9 => x=4,5`
`(2x+1)/5=-2 => 2x+1=-10 => 2x=-11 => x=-5,5`
`(2x+1)/5=0 => 2x+1=0 => 2x=-1 => x=-0,5`
`(2x+1)/5=4 => 2x+1=20 => 2x=19 => x=9,5`
`b)`
`(x+1)/7=0 => x+1=0 => x=-1`
`(3x+3)/5=0 => 3x+3=0 => x=-1`
`(2x(x+1))/(3x+4)=0 => 2x(x+1)=0 =>` \(\left[ \begin{array}{l}2x=0\\x+1=0\end{array} \right.\) `=>` \(\left[ \begin{array}{l}x=0\\x=-1\end{array} \right.\)
`(3x(x-5))/(x-7)=0 => 3x(x-5)=0 =>` \(\left[ \begin{array}{l}3x=0\\x-5=0\end{array} \right.\) `=>` \(\left[ \begin{array}{l}x=0\\x=5\end{array} \right.\)
