a) `3(2-x)+5(x-6)=-98`
`6-3x+5x-30=-98`
`-3x+5x=-98-6+30`
`2x=-74`
`x=-37`
b) `(x+7)(8-x)=0`
\(\left[{}\begin{matrix}x+7=0\\8-x=0\end{matrix}\right.\\ \left[{}\begin{matrix}x=-7\\x=8\end{matrix}\right.\)
a, \(3\left(2-x\right)+5\left(x-6\right)=-98\)
\(6-3x+5x-30=-98\)
\(2x-24=-98\)
\(2x=-74\)
\(x=-37\)
b,\(\left(x+7\right)\left(8-x\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=-7\\x=8\end{matrix}\right.\)
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Giải:
a) \(3.\left(2-x\right)+5.\left(x-6\right)=-98\)
\(6-3x+5x-30=-98\)
\(-3x+5x=-98-6+30\)
\(2x=-74\)
\(x=-74:2\)
\(x=-37\)
b) \(\left(x+7\right).\left(8-x\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}x+7=0\\8-x=0\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=-7\\x=8\end{matrix}\right.\)
Chúc bạn học tốt!