计算:(1)(-3a)3-(-a)?(-3a)2(2)4-(-2)-2-32÷(3.14-π)0(3)-0.2514×230(4)1982(5)(-2x)?2?(-0

发布时间:2020-08-09 00:59:35

计算:
(1)(-3a)3-(-a)?(-3a)2
(2)4-(-2)-2-32÷(3.14-π)0
(3)-0.2514×230
(4)1982
(5)(-2x)?2?(-0.5xy3);
(6)(3x2y-2x+1)(-2xy)
(7)(-4x-y)(4x-y)
(8)-3a(a-b)2;
(9)(a+2b-3c)(a-2b-3c)
(10)(2a+b)2(2a-b)2

网友回答

解:(1)(-3a)3-(-a)?(-3a)2,
=-27a3+a×9a2,
=-18a3;

(2)4-(-2)-2-32÷(3.14-π)0,
=4--9×1,
=-;

(3)-0.2514×230,
=-()14×230,
=-2-28×230,
=-4;

(4)1982=(200-2)2,
=2002-2×200×2+22,
=40000-800+4,
=39204;
(5)(-2x)?2?(-0.5xy3),
=4x2?(-xy3),
=-2x3y3;

(6)(3x2y-2x+1)(-2xy),
=3x2y?(-2xy)+(-2x)?(-2xy)+1?(-2xy),
=-6x3y2+4x2y-2xy;

(7)(-4x-y)(4x-y),
=(-y-4x)(-y+4x),
=(-y)2-(4x)2,
=y2-16x2;

(8)-3a(a-b)2,
=-3a(a2-2ab+b2),
=-3a?a2-(-3a)?2ab+(-3a)?b2,
=-3a3+6a2b-3ab2;

(9)(a+2b-3c)(a-2b-3c),
=(a-3c+2b)(a-3c-2b),
=(a-3c)2-(2b)2,
=(a2-6ac+9c2)-4b2,
=a2-6ac+9c2-4b2;

(10)(2a+b)2(2a-b)2,
=[(2a+b)(2a-b)]2,
=[(2a)2-b2]2,
=(4a2-b2)2,
=16a4-8a2b2+b4.
解析分析:根据整式的运算顺序,先算乘除,后算加减,有括号先算括号里面的,乘法运算时,系数与系数相乘,相同字母与相同字母相乘,底数不变指数相加,再根据整式除法法则,系数与系数相除,相同字母与相同字母相除,底数不变指数相减,能用完全公式或平方差公式的可运用公式,可减小计算量,分别得出结果即可.

点评:此题主要考查了整式的混合运算,以及运用公式进行整式运算,题难度不大,关键是注意运算的顺序以及符号问题.
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