两个连续的奇数之和是什么,它们的平方差为56?
(A) 30
(B) 28
(C) 34
(D) 32答案: (B)
解释:
Let the no. be x and (x +2).
Then (x + 2)2 – x2 = 56
4x + 4 = 56
x + 1 = 14
x = 13
Sum of numbers = x + (x +2) = 28
这个问题的测验
📅  最后修改于: 2021-05-13 21:29:22             🧑  作者: Mango
两个连续的奇数之和是什么,它们的平方差为56?
(A) 30
(B) 28
(C) 34
(D) 32答案: (B)
解释:
Let the no. be x and (x +2).
Then (x + 2)2 – x2 = 56
4x + 4 = 56
x + 1 = 14
x = 13
Sum of numbers = x + (x +2) = 28
这个问题的测验