1) (2,18+0,4280,35)-15-3824 2) 2,4x - 7,8x+0,52=1 3) 20: (6²+1)+(1 2/3 - 5,8):5

\[ (2.18 + 0.428 \cdot 0.35) - 15 - 3824 \]
\[ (2.18 + 0.1498) - 15 - 3824 \]
\[ 2.3298 - 15 - 3824 \]
\[ -12.6702 - 3824 \]
\[ -3836.6702 \]

\[ 2.4x - 7.8x + 0.52 = 1 \]
\[ -5.4x + 0.52 = 1 \]
\[ -5.4x = 1 - 0.52 \]
\[ -5.4x = 0.48 \]
\[ x = \frac{0.48}{-5.4} = -\frac{48}{540} = -\frac{4}{45} \]
Приблизительное значение: \( x \approx -0.0889 \)

\[ 20 : (6^2 + 1) + (1 \frac{2}{3} - 5.8) : 5 \]
\[ 20 : (36 + 1) + (\frac{5}{3} - \frac{58}{10}) : 5 \]
\[ 20 : 37 + (\frac{50}{30} - \frac{174}{30}) : 5 \]
\[ \frac{20}{37} + (-\frac{124}{30}) : 5 \]
\[ \frac{20}{37} - \frac{124}{30 \cdot 5} \]
\[ \frac{20}{37} - \frac{124}{150} \]
\[ \frac{20}{37} - \frac{62}{75} \]
\[ \frac{20 \cdot 75 - 62 \cdot 37}{37 \cdot 75} \]
\[ \frac{1500 - 2294}{2775} \]
\[ \frac{-794}{2775} \]
Приблизительное значение: \( \approx -0.2861 \)