a) -5/2 : (3/4 -1/2)
b) 298/719 : ( 1/4 + 1/12 – 1/3 ) – 2011/2012
c) 27.18+27.103-120.27/15.33+33.12
d) |x-1/3|= 5/6
a) -5/2 : (3/4 -1/2)
b) 298/719 : ( 1/4 + 1/12 – 1/3 ) – 2011/2012
c) 27.18+27.103-120.27/15.33+33.12
d) |x-1/3|= 5/6
a) -5/2 : (3/4 -1/2)
= -5/2 : 1/4
= -5/2 . 4
= -10
b) 298/719 : ( 1/4 + 1/12 – 1/3 ) – 2011/2012
= – 2011/2012
= ko xác định vì 298/719 : 0 là ko thể.
c) 27.18 + 27.103 – 120.27/15.33 + 33.12
= 27 ( 18 + 103 ) – 72/11 + 396
= 27 . 121 – 72/11 + 396
= 3267 – 72/11 + 396
= 3656,45454545
d) |x-1/3|= 5/6
+) x-1/3 = 5/6
x = 5/6 + 2/6 = 7/6
+) x-1/3 = -5/6
x = -5/6 + 2/6 = -3/6 = -1/2
a) $\frac{-5}{2}:\left ( \frac{3}{4}-\frac{1}{2} \right )$
$=\frac{-5}{2}:\frac{1}{4}$
$=-\frac{5}{2}.4$
$=-5.2=-10$
b) $\frac{298}{719}:\left ( \frac{1}{4}+\frac{1}{12}-\frac{1}{3}-\frac{2011}{2012} \right )$
$=\frac{298}{719}:\left ( -\frac{2011}{2012} \right )$
$=-\frac{298}{719}.\frac{2012}{2011}=-\frac{599576}{1445909}$
c) $27.18+27.103-\frac{120.27}{15.33}+33.12$
$=27,18+27,103-\frac{\frac{12027}{100}}{\frac{1533}{100}}+33,12$
$=27,18+27,103-\frac{12027}{1533}+33,12$
$=87,403-\frac{12027}{1533}$
$=\frac{87403}{1000}-\frac{12027}{1533}=\frac{40653933}{511000}$
d) $\left | x-\frac{1}{3} \right |=\frac{5}{6}$
$\Leftrightarrow \left[ \begin{array}{l}x-\frac{1}{3}=\frac{5}{6}\\x-\frac{1}{3}=-\frac{5}{6}\end{array} \right.$
$\Leftrightarrow \left[ \begin{array}{l}x=\frac{7}{6}\\x=-\frac{1}{2}\end{array} \right.$
Vậy $x\in\left \{ \frac{7}{6} ; -\frac{1}{2} \right \} $