问题
解答题
计算: (1)
(2)2x2y•(-3xy)÷(xy)2; (3)(-2a)•(3a2-a+3); (4)(x+3)(x+4)-(x-1)2; (5)(x4+2x3-
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答案
(1)原式=0.5-2+2=0.5;
(2)原式=-6x3y2÷x2y2=6x;
(3)原式=-6a3+2a2-6a;
(4)原式=x2+7x+12-x2+2x-1=9x+11;
(5)原式=(x4+2x3-
x2)÷1 2
=4x4+8x3-2x2.1 4