Đáp án:
Giải thích các bước giải:
a, $\frac{-5}{3}$ . x = $\frac{4}{5}$
x = $\frac{4}{5}$ : $\frac{-5}{3}$
x = $\frac{4}{5}$ . $\frac{3}{-5}$
x = $\frac{12}{-25}$
Vậy x = $\frac{12}{-25}$
b, $\frac{-5}{3}$ . x = $\frac{-4}{5}$
x = $\frac{-4}{5}$ : $\frac{-5}{3}$
x = $\frac{-4}{5}$ . $\frac{3}{-5}$
x = $\frac{-12}{-25}$ ⇒ $\frac{12}{25}$
Vậy x = $\frac{12}{25}$
c, $\frac{17}{-4}$ . x - $\frac{1}{2}$ = $\frac{3}{4}$
$\frac{17}{-4}$ . x = $\frac{3}{4}$ + $\frac{1}{2}$
$\frac{17}{-4}$ . x = $\frac{3}{4}$ + $\frac{2}{4}$
$\frac{17}{-4}$ . x = $\frac{5}{4}$
x = $\frac{5}{4}$ : $\frac{17}{-4}$
x = $\frac{5}{4}$ . $\frac{-4}{17}$
x = $\frac{-20}{68}$ ⇒ $\frac{-5}{17}$
Vậy x = $\frac{-5}{17}$
d, $\frac{1}{4}$ + $\frac{3}{4}$ : x = $\frac{1}{2}$
$\frac{3}{4}$ : x = $\frac{1}{2}$ - $\frac{1}{4}$
$\frac{3}{4}$ : x = $\frac{2}{4}$ - $\frac{1}{4}$
$\frac{3}{4}$ : x = $\frac{1}{4}$
x = $\frac{3}{4}$ : $\frac{1}{4}$
x = $\frac{3}{4}$ . $\frac{4}{1}$
x = $\frac{12}{4}$ = 3
Vậy x = 3
