Đáp án:
Bài 2 ;
a)2x+27=-11
=>2x=-11-27
=>2x=-38
=>x = -38 : 2
=>x = -19
Vậy x={-19}
b) $\dfrac{2}{3}$x - $\dfrac{1}{2}$ = $\dfrac{1}{10}$
=>$\dfrac{2}{3}$x = $\dfrac{1}{10}$ + $\dfrac{1}{2}$
=>$\dfrac{2}{3}$x =$\dfrac{2}{3}$
=> x = $\dfrac{2}{3}$ : $\dfrac{2}{3}$
=>x = 1
Vậy x={1}
c) $\dfrac{1}{3}$ + $\dfrac{2}{3}$ : x = -7
=> $\dfrac{2}{3}$ : x = -7 - $\dfrac{1}{3}$
=> $\dfrac{2}{3}$ : x = $\dfrac{-22}{3}$
=>x = $\dfrac{2}{3}$ : $\dfrac{-22}{3}$
=>x = $\dfrac{-1}{11}$
Vậy x={ $\dfrac{-1}{11}$
d) $\dfrac{x}{5}$=$\dfrac{2}{3}$
=> x= 5 . 2 : 3
=>x = $\dfrac{10}{3}$
Vậy x = {$\dfrac{10}{3}$}
e) - $\dfrac{13}{20}$+x = $\dfrac{11}{15}$
=> x = $\dfrac{11}{15}$ + $\dfrac{13}{20}$
=>x = $\dfrac{83}{60}$
Vậy x= { $\dfrac{83}{60}$ }
f) x + $\dfrac{7}{12}$ = $\dfrac{-5}{6}$
=> x=$\dfrac{-5}{6}$ - $\dfrac{7}{12}$
=>x=$\dfrac{-1}{4}$
Vậy x={$\dfrac{-1}{4}$}
