题目

计算: (1) (2) 答案: 解: |−3|−4+(2−1)0−(−5) =3−2+1+5 =7 ; 解: 2x+1x2+2x+3x2+2x =−2x+4x2+2x =2(x+2)x(x+2) =2x ;
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