Đáp án:
$\frac{25}{108}$
Giải thích các bước giải:
1$\frac{1}{30}$ : ( 24$\frac{1}{6}$ - 24$\frac{1}{5}$ ) - $\frac{1\frac{1}{2}-\frac{3}{4}}{4x-\frac{1}{2}}$ = ( -1$\frac{1}{15}$ ) : ( 8$\frac{1}{5}$ - 8$\frac{1}{3}$) (1)
Ta có:
1$\frac{1}{30}$ : ( 24$\frac{1}{6}$ - 24$\frac{1}{5}$ )
= $\frac{31}{30}$ : ( $\frac{145}{6}$ - $\frac{121}{5}$ )
= $\frac{31}{30}$ : $\frac{-1}{30}$
1$\frac{1}{2}$-$\frac{3}{4}$
= $\frac{3}{2}$ - $\frac{3}{4}$
= $\frac{6-3}{4}$
= $\frac{3}{4}$
= -31
( -1$\frac{1}{15}$ ) : ( 8$\frac{1}{5}$ - 8$\frac{1}{3}$)
= $\frac{-16}{15}$ : ($\frac{1}{5}$ - $\frac{1}{3}$ )
= $\frac{-16}{15}$ : $\frac{-2}{15}$
= 8
Suy ra:
(1) ⇔ -31 - $\frac{3}{4(4x -\frac{1}{2})}$ = 8
⇔ -31 - $\frac{3}{16x -2}$ = 8
⇔ $\frac{3}{16x -2}$ = -39
⇔ 16x - 2 = $\frac{3}{-39}$ = -$\frac{1}{13}$
⇔ 16x = 2 - $\frac{1}{13}$ = $\frac{26-1}{13}$ = $\frac{25}{13}$
⇔ x = $\frac{25}{13x16}$ = $\frac{25}{108}$
