Câu 1:
a. -$\frac{2}{9}$ - $\frac{1}{3}$
= $\frac{-2}{9}$ + $\frac{-1}{3}$
= $\frac{-2}{9}$ + $\frac{-3}{9}$
= $\frac{-5}{9}$
b. |-4|.$\frac{7}{2³}$
= 4.$\frac{7}{8}$
= 1.$\frac{7}{2}$
= $\frac{7}{2}$
Câu 2:
1)
a. x = 24.25%
x = 6 (kg)
b. x : 4$\frac{2}{5}$ = -2,5
x : $\frac{22}{5}$ = $\frac{-5}{2}$
x = $\frac{-5}{2}$. $\frac{22}{5}$
x = $\frac{-1}{1}$. $\frac{11}{1}$
x = -11
2) -$\frac{2}{3}$ - $\frac{5}{12}$ < x $\leq$ 4 - $\frac{1}{3}$ : $\frac{1}{6}$
$\frac{-2}{3}$ + $\frac{-5}{12}$ < x $\leq$ 4 - $\frac{1}{3}$.6
$\frac{-8}{12}$ + $\frac{-5}{12}$ < x $\leq$ 4 - $\frac{1}{1}$.2
$\frac{-13}{12}$ < x $\leq$ 4 - 2
-1$\frac{1}{12}$ < x $\leq$ 2
⇒ x ∈ {-1; 0; 1}
