问题 解答题 (1)计算:|-3|+4+(1-2)0-tan45°;(2)化简:a2a-1-a-1. 答案 (1)原式=3+2+1-1=5;(2)原式=a2a-1-a2-1a-1=a2-a2+1a-1=1a-1.