`a)(x-2)(x^2+1)=0`
`→x-2=0` (vì `x^2+1≥1`)
`→x=2`
Vậy `x=2`
`b)(x-1)(x-2)=0`
`→` \(\left[ \begin{array}{l}x-1=0\\x-2=0\end{array} \right.\)
`→` \(\left[ \begin{array}{l}x=1\\x=2\end{array} \right.\)
Vậy `x∈{1;2}`
`c)(x+1)(x^2-4)=0`
`→` \(\left[ \begin{array}{l}x+1=0\\x^2-4=0\end{array} \right.\)
`→` \(\left[ \begin{array}{l}x=-1\\x=±2\end{array} \right.\)
Vậy `x∈{1;2;-2}`
`d)13(x-5)=-169`
`→13x-65=-169`
`→13x=-169+65`
`→13x=104`
`→x=-8`
Vậy `x=-8`
`f)x.y=1261` và `x-y=?`
`e)2|4-x|=|-8|`
`→2|4-x|=8`
`→|4-x|=4`
`→` \(\left[ \begin{array}{l}4-x=4\\4-x=-4\end{array} \right.\)
`→` \(\left[ \begin{array}{l}x=0\\x=8\end{array} \right.\)
Vậy `x∈{0;8}`
