Đáp án:
Giải thích các bước giải:
a) |3x-2| - x = 7
↔ 3x - 2 - x = 7
↔ (3x - x) - 2 = 7
↔ 2x -2 = 7
↔ 2x = 7 + 2
↔ 2x = 9
↔ x = $\frac{9}{2}$
Vậy x = $\frac{9}{2}$
b) | x + $\frac{3}{4}$ | - $\frac{1}{3}$ = 0
↔ x + $\frac{3}{4}$ - $\frac{1}{3}$ = 0
↔ x + ( $\frac{3}{4}$ - $\frac{1}{3}$ ) = 0
↔ x + $\frac{5}{12}$ = 0
↔ x = 0 - $\frac{5}{12}$
↔ x = - $\frac{5}{12}$
Vậy x = - $\frac{5}{12}$
c) Ta có :
$(\frac{1}{32})^{7}$ = $\frac{1^{7}}{32^{7}}$ = $\frac{1}{(2^{5})^{7}}$ = $\frac{1}{2^{35}}$
$(\frac{1}{16})^{9}$ = $\frac{1^{9}}{16^{9}}$ = $\frac{1}{(2^{4})^{9}}$ = $\frac{1}{2^{36}}$
Vì $2^{35}$ < $2^{36}$ → $\frac{1}{2^{35}}$ > $\frac{1}{2^{36}}$
Vậy $(\frac{1}{32})^{7}$ > $(\frac{1}{16})^{9}$
