计算:(1)(-7)+(-3)+(+9)+(-1);(2)(-5)-(-7);(3)13-12-34+23;(4)(-225)×(-34)÷(-335);(5)881×634-(-27)÷(-157)+(0.5)2;(6)-(-3)2+(-3)2-(-1)3×(13-12)÷16-|-5|.-数学
题文
计算: (1)(-7)+(-3)+(+9)+(-1); (2)(-5)-(-7); (3)
(4)(-2
(5)
(6)-(-3)2+(-3)2-(-1)3×(
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答案
(1)原式=-7-3+9-1 =-10+9-1 =-1-1 =-2; (2)原式=-5+7 =2; (3)原式=
=1-
=-
(4)原式=-
=-
(5)原式=
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