计算 (1)(−1)2006+(−1/2)−2−(3.14−π)0 (2)(x-3)(x+2)-(x+1)2 (3)(6m2n-6m2n2-3m2)÷(-3m2)

问题描述:

计算
(1)(−1)2006+(−

1
2
)−2−(3.14−π)0                                 
(2)(x-3)(x+2)-(x+1)2
(3)(6m2n-6m2n2-3m2)÷(-3m2

(1)原式=1+4-1=4;
(2)原式=x2+2x-3x-6-x2-2x-1=-3x-7;
(3)原式=-2n+2n2+1.