2. Реши уравнения: a) 16/21 * x - 2.48 = 3/7 * x - 1.18; б) 5(1 - 2y) = 7 - 4(3y + 1).

Решение:

1. а) \( \frac{16}{21}x - 2.48 = \frac{3}{7}x - 1.18 \)
   \( \frac{16}{21}x - \frac{9}{21}x = 2.48 - 1.18 \)
   \( \frac{7}{21}x = 1.3 \)
   \( \frac{1}{3}x = 1.3 \)
   \( x = 1.3 \cdot 3 \)
   \( x = 3.9 \)
2. б) \( 5(1 - 2y) = 7 - 4(3y + 1) \)
   \( 5 - 10y = 7 - 12y - 4 \)
   \( 5 - 10y = 3 - 12y \)
   \( -10y + 12y = 3 - 5 \)
   \( 2y = -2 \)
   \( y = -1 \)

Ответ: а) x = 3.9; б) y = -1.