Bài 1:
a)= $\frac{2}{3}$ - 4($\frac{1}{2}$ + $\frac{3}{4}$)
= $\frac{2}{3}$ - 4.$\frac{5}{4}$
= $\frac{2}{3}$ - 5
= $\frac{-13}{3}$
b)= -$\frac{5}{9}$ - $\frac{3}{11}$ - $\frac{13}{6}$.$\frac{1}{11}$
= -$\frac{5}{9}$ - $\frac{3}{11}$ - $\frac{13}{66}$
= -$\frac{203}{198}$
c)= $\frac{1}{2}$.11 - 7
= $\frac{11}{2}$ - 7
= -$\frac{3}{2}$
d)= ($\frac{32}{15}$.$\frac{9}{17}$.$\frac{3}{32}$) : (-$\frac{3}{17}$)
= ($\frac{1}{5}$.$\frac{9}{17}$) : ($\frac{-3}{17}$)
= $\frac{9}{85}$ : ($\frac{-3}{17}$)
= -$\frac{9}{85}$. $\frac{17}{3}$
= -$\frac{3}{5}$
Bài 2:
a) ↔ $\frac{140}{210}$x + $\frac{150}{210}$ = $\frac{63}{210}$
↔ 140x + 150 = 63
↔ 140x = 63 - 150
↔ 140x= -87
↔ x= -$\frac{87}{140}$
Vậy...
b) ↔ $\frac{21}{28}$x - $\frac{14}{28}$ = -$\frac{12}{28}$
↔ 21x - 14 = -12
↔ 21x = -12 + 14
↔ 21x= 2
↔ x= $\frac{2}{21}$
Vậy...
c) ↔ -$\frac{21}{13}$x + $\frac{1}{3}$ = -$\frac{2}{3}$
↔ -$\frac{63}{39}$x + $\frac{13}{39}$ = -$\frac{26}{39}$
↔ -63x + 13 = -26
↔ -63x = -26 -13
↔ -63x = -39
↔ x = $\frac{13}{21}$
Vậy...
