Решение:
- \( 7x - 4x = 16 \)
\( 3x = 16 \)
\( x = \frac{16}{3} \) - \( 13 - 8 = -2x + 5x \)
\( 5 = 3x \)
\( x = \frac{5}{3} \) - \( 4y - 6y = 17 - 15 \)
\( -2y = 2 \)
\( y = -1 \) - \( 1.3a - 0.8a = 5 + 11 \)
\( 0.5a = 16 \)
\( a = 32 \) - \( 0.71y + 0.29y = 10 + 13 \)
\( y = 23 \) - \( 8c + 8c = 4.61 - 0.73 \)
\( 16c = 3.88 \)
\( c = \frac{3.88}{16} = 0.2425 \)
Ответ: 1) x = \(\frac{16}{3}\); 2) x = \(\frac{5}{3}\); 3) y = -1; 4) a = 32; 5) y = 23; 6) c = 0.2425.