\[ 10^x - \frac{5^x}{5} \cdot \frac{2^x}{4} = 950 \]
\[ 10^x - \frac{(5 \cdot 2)^x}{20} = 950 \]
\[ 10^x - \frac{10^x}{20} = 950 \]
\[ 10^x \left(1 - \frac{1}{20}\right) = 950 \]
\[ 1 - \frac{1}{20} = \frac{20}{20} - \frac{1}{20} = \frac{19}{20} \]
\[ 10^x \cdot \frac{19}{20} = 950 \]
\[ 10^x = 950 \cdot \frac{20}{19} \]
\[ 10^x = 50 \cdot 20 \]
\[ 10^x = 1000 \]
\[ 1000 = 10^3 \]
\[ x = 3 \]
Ответ: x = 3