Giải thích các bước giải:
Tính
`(2+5)-(-1-4)`
`=7+5`
`=12`
`+6-(-1+30)`
`=6+1-30`
`=7-30`
`=-23`
`+8-(-3+1)`
`=8+3-1`
`=11-1`
`=10`
`10+(4-1) `
`=10+3`
`=13`
`(3+1)-(2-1)`
`=4-1`
`=3`
Tìm `x`
`(2x-1).(2x)=0`
`=>`\(\left[ \begin{array}{l}2x-1=0\\2x=0\end{array} \right.\)
`=>`\(\left[ \begin{array}{l}2x=1\\x=0\end{array} \right.\)
`=>`\(\left[ \begin{array}{l}x=\dfrac{1}{2}\\x=0\end{array}\right .\)
` (3x-6).x=0`
`=>`\(\left[ \begin{array}{l}3x-6=0\\x=0\end{array} \right.\)
`=>`\(\left[ \begin{array}{l}3x=6\\x=0\end{array} \right.\)
`=>`\(\left[ \begin{array}{l}x=2\\x=0\end{array} \right.\)
`2x.(3x+1)=0`
`=>`\(\left[ \begin{array}{l}2x=0\\3x+1=0\end{array} \right.\)
`=>`\(\left[ \begin{array}{l}x=0\\3x=-1\end{array} \right.\)
`=>`\(\left[ \begin{array}{l}x=0\\x=\dfrac{-1}{3}\end{array} \right.\)
` (5x-1).(2x+1)=0`
`=>`\(\left[ \begin{array}{l}5x-1=0\\x=2x+1=0\end{array} \right.\)
`=>`\(\left[ \begin{array}{l}5x=1\\2x=-1\end{array} \right.\)
`=>`\(\left[ \begin{array}{l}x=\dfrac{1}{5}\\x=\dfrac{-1}{2}\end{array} \right.\)
`(8x+3).(x+1)=0`
`=>`\(\left[ \begin{array}{l}8x+3=0\\x+1=0\end{array} \right.\)
`=>`\(\left[ \begin{array}{l}8x=-3\\x=-1\end{array} \right.\)
`=>`\(\left[ \begin{array}{l}x=\dfrac{-3}{8}\\x=-1\end{array} \right.\)
