1. 去括号：
(1)$4a - 2(b - 3c) = $
(3)$3x + [4y - (7z + 3)] = $
(1)$4a - 2(b - 3c) = $
$4a - 2b + 6c$
； (2)$-5a + \frac{1}{2}(4x - 6) = $$-5a + 2x - 3$
；(3)$3x + [4y - (7z + 3)] = $
$3x + 4y - 7z - 3$
； (4)$-3a^{3} - [2x^{2} - (5x + 1)] = $$-3a^{3} - 2x^{2} + 5x + 1$
.答案：1. (1)$4a - 2b + 6c$ (2)$-5a + 2x - 3$ (3)$3x + 4y - 7z - 3$ (4)$-3a^{3} - 2x^{2} + 5x + 1$
解析：
1. (1)解：$4a - 2(b - 3c) = 4a - 2b + 6c$
(2)解：$-5a + \frac{1}{2}(4x - 6) = -5a + 2x - 3$
(3)解：$3x + [4y - (7z + 3)] = 3x + 4y - 7z - 3$
(4)解：$-3a^{3} - [2x^{2} - (5x + 1)] = -3a^{3} - 2x^{2} + 5x + 1$
(2)解：$-5a + \frac{1}{2}(4x - 6) = -5a + 2x - 3$
(3)解：$3x + [4y - (7z + 3)] = 3x + 4y - 7z - 3$
(4)解：$-3a^{3} - [2x^{2} - (5x + 1)] = -3a^{3} - 2x^{2} + 5x + 1$
2. 填空：
(1)$2 - x^{2} + 2xy - y^{2} = 2 - ($
(3)$5x + 3x^{2} - 4y^{2} = 5x - ($
(1)$2 - x^{2} + 2xy - y^{2} = 2 - ($
$x^{2} - 2xy + y^{2}$
$)$；(2)$a - (b - c + d) = a - d + ($$-b + c$
$)$；(3)$5x + 3x^{2} - 4y^{2} = 5x - ($
$4y^{2} - 3x^{2}$
$)$； (4)$-3p + 3q - 1 = 3q - ($$3p + 1$
$)$.答案：2. (1)$x^{2} - 2xy + y^{2}$ (2)$-b + c$ (3)$4y^{2} - 3x^{2}$ (4)$3p + 1$
3. 先去括号,再合并同类项：
(1)$a - (2a - 2)$； (2)$-(5x + y) - 3(2x - 3y)$；
(3)$-(3a^{2} - 2a + 1) + (a^{2} - 5a + 7)$； (4)$3a^{2}b - 2[ab^{2} - 2(a^{2}b - 2ab^{2})]$；
(5)$2(a^{2}b - 3ab^{2}) - 3(2ab^{2} - \frac{5}{6}a^{2}b)$； (6)$(x + 3) - (y - 2x) + (2y - 1)$.
(1)$a - (2a - 2)$； (2)$-(5x + y) - 3(2x - 3y)$；
(3)$-(3a^{2} - 2a + 1) + (a^{2} - 5a + 7)$； (4)$3a^{2}b - 2[ab^{2} - 2(a^{2}b - 2ab^{2})]$；
(5)$2(a^{2}b - 3ab^{2}) - 3(2ab^{2} - \frac{5}{6}a^{2}b)$； (6)$(x + 3) - (y - 2x) + (2y - 1)$.
答案：3. (1)$-a + 2$ (2)$-11x + 8y$ (3)$-2a^{2} - 3a + 6$ (4)$7a^{2}b - 10ab^{2}$ (5)$\frac{9}{2}a^{2}b - 12ab^{2}$ (6)$3x + y + 2$
解析：
(1)解：原式$=a - 2a + 2 = -a + 2$
(2)解：原式$= -5x - y - 6x + 9y = -11x + 8y$
(3)解：原式$= -3a^{2} + 2a - 1 + a^{2} - 5a + 7 = -2a^{2} - 3a + 6$
(4)解：原式$= 3a^{2}b - 2(ab^{2} - 2a^{2}b + 4ab^{2}) = 3a^{2}b - 2(5ab^{2} - 2a^{2}b) = 3a^{2}b - 10ab^{2} + 4a^{2}b = 7a^{2}b - 10ab^{2}$
(5)解：原式$= 2a^{2}b - 6ab^{2} - 6ab^{2} + \frac{5}{2}a^{2}b = \frac{9}{2}a^{2}b - 12ab^{2}$
(6)解：原式$= x + 3 - y + 2x + 2y - 1 = 3x + y + 2$
(2)解：原式$= -5x - y - 6x + 9y = -11x + 8y$
(3)解：原式$= -3a^{2} + 2a - 1 + a^{2} - 5a + 7 = -2a^{2} - 3a + 6$
(4)解：原式$= 3a^{2}b - 2(ab^{2} - 2a^{2}b + 4ab^{2}) = 3a^{2}b - 2(5ab^{2} - 2a^{2}b) = 3a^{2}b - 10ab^{2} + 4a^{2}b = 7a^{2}b - 10ab^{2}$
(5)解：原式$= 2a^{2}b - 6ab^{2} - 6ab^{2} + \frac{5}{2}a^{2}b = \frac{9}{2}a^{2}b - 12ab^{2}$
(6)解：原式$= x + 3 - y + 2x + 2y - 1 = 3x + y + 2$