Упростить выражения: 1) 3c + 4c - 8c 2) -4t + 3t - 8 - 7t 3) 8x - 8y + 2y - 6x 4) -a + 3b - 4b + 1,5a 5) 2(5x - 3) - 5(3 - 2x) 6) -(3a - 2) + 5(a - 2) 7) 1 1/3a - 2/3a - a 8) 3/5b + 1/10b - 7/10b 9) (2x - y - 3) · (-2) - 2(2x - y)

Решение:

1. \( 3c + 4c - 8c = (3 + 4 - 8)c = -1c = -c \)
2. \( -4t + 3t - 8 - 7t = (-4 + 3 - 7)t - 8 = -8t - 8 \)
3. \( 8x - 8y + 2y - 6x = (8 - 6)x + (-8 + 2)y = 2x - 6y \)
4. \( -a + 3b - 4b + 1,5a = (-1 + 1,5)a + (3 - 4)b = 0,5a - b \)
5. \( 2(5x - 3) - 5(3 - 2x) = 10x - 6 - 15 + 10x = (10 + 10)x + (-6 - 15) = 20x - 21 \)
6. \( -(3a - 2) + 5(a - 2) = -3a + 2 + 5a - 10 = (-3 + 5)a + (2 - 10) = 2a - 8 \)
7. \( 1\frac{1}{3}a - \frac{2}{3}a - a = \frac{4}{3}a - \frac{2}{3}a - \frac{3}{3}a = (\frac{4 - 2 - 3}{3})a = \frac{-1}{3}a = -\frac{1}{3}a \)
8. \( \frac{3}{5}b + \frac{1}{10}b - \frac{7}{10}b = \frac{6}{10}b + \frac{1}{10}b - \frac{7}{10}b = (\frac{6 + 1 - 7}{10})b = \frac{0}{10}b = 0 \)
9. \( (2x - y - 3) \cdot (-2) - 2(2x - y) = -4x + 2y + 6 - 4x + 2y = (-4 - 4)x + (2 + 2)y + 6 = -8x + 4y + 6 \)

Ответ: 1) -c; 2) -8t - 8; 3) 2x - 6y; 4) 0,5a - b; 5) 20x - 21; 6) 2a - 8; 7) -1/3a; 8) 0; 9) -8x + 4y + 6.