\[ \frac{4(2c-1)}{36} + \frac{9c}{36} = \frac{6(c+3)}{36} \]
\[ 4(2c-1) + 9c = 6(c+3) \]
\[ 8c - 4 + 9c = 6c + 18 \]
\[ 17c - 4 = 6c + 18 \]
\[ 17c - 6c = 18 + 4 \]11c = 22
\[ c = \frac{22}{11} \]c = 2
Ответ: c = 2