计算:(1)(-3)+(+9)(2)-20+(+3)-(-5)-(+7)(3)(-7)×(-5)-90÷(-15)(4)-102+[(-4)2+(3+32)×2]÷(-2)3.
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计算下列各题: (1)23-17-(-7)+(-16) (2) = = (3) = (4)-1× =