4. Упростите выражения: 1) -3 \(\cdot\) (2a - 3b) + 4 \(\cdot\) (5a - 7b); 2) 16 \(\cdot\) (-5m - 2n) - 8 \(\cdot\) (3m - 4n); 3) 6 \(\cdot\) (x - 2y) - 3 \(\cdot\) (-4x - 5y); 4) -3 \(\cdot\) (-2b - 4c) + 5 \(\cdot\) (-3b + 2c).

4. Упрощение выражений:

1. \( -3(2a - 3b) + 4(5a - 7b) = -6a + 9b + 20a - 28b = (-6a + 20a) + (9b - 28b) = \textbf{14a - 19b} \)
2. \( 16(-5m - 2n) - 8(3m - 4n) = -80m - 32n - 24m + 32n = (-80m - 24m) + (-32n + 32n) = \textbf{-104m} \)
3. \( 6(x - 2y) - 3(-4x - 5y) = 6x - 12y + 12x + 15y = (6x + 12x) + (-12y + 15y) = \textbf{18x + 3y} \)
4. \( -3(-2b - 4c) + 5(-3b + 2c) = 6b + 12c - 15b + 10c = (6b - 15b) + (12c + 10c) = \textbf{-9b + 22c} \)

Ответ: 1) \( 14a - 19b \); 2) \( -104m \); 3) \( 18x + 3y \); 4) \( -9b + 22c \).