【单选题】
网考网参考答案：C
网考网解析：
B-A= (51 +52+53+...+99+ 100) -(1 +2+3+...+49+50) = (51-1)+(52-2)+(53-3)+...+(99-49)+(100-50) = 50 + 50 + 50 +...+ 50 + 50 = 50 × 50 = 2500. **If you know the formula, for adding up the first n positive integers, you can use it: A = = 25(51) = 1275. B is the sum of the integers from 1 to 100 minus the sum of the integers from 1 to 50: B = -1275 = 50(101) -1275 = 5050 -1275 = 3875. Finally, B -A = 3875 -1275 = 2500. The columns are equal (C). document.getElementById("warp").style.display="none"; document.getElementById("content").style.display="block"; 查看试题解析出处>>
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