Bài 2
1.a.$3x$ - $7$ = $\frac{1}{2}$
$3x$ = $\frac{1}{2}$ +$7$
$3x$ = $\frac{15}{2}$
$x$ = $\frac{5}{2}$
b. $\frac{27}{x}$ =$\frac{3.6}{-2}$
$\frac{27}{x}$ =$\frac{18}{-2}$
$\frac{27}{x}$ = $-9$
$27$ : $x$ = $-9$
$x$ = $-3$
c. $|x - 10 |$ = $2015$
⇒\(\left[ \begin{array}{l}x-10=2015\\x-10=-2015\end{array} \right.\)
⇒\(\left[ \begin{array}{l}x=2025\\x=-2005\end{array} \right.\)
$Vậy$ $x$ $∈$ {$2025 , -2005$}
2. $12$ .($-5$) = ($-3$). $20$
⇒$\frac{12}{-3}$ =$\frac{20}{-5}$ ,$\frac{12}{20}$ =$\frac{-3}{-5}$ ,$\frac{-5}{-3}$ =$\frac{20}{12}$ ,$\frac{-5}{20}$ =$\frac{-3}{12}$
$vuatoanhoc$
