如何确定两对数字相等

Question

我有两对数字。假设我有（A，B）和（X，Y） 问题是：

if 
A-B = X-Y and
A+B = X+Y and
A/B = X/Y and 
A*B = X*Y

我可以得出结论A = X和B = Y吗？

Answer 1

我相信：

A-B = X-Y so
A = X-Y+B and
B = -X+Y+A so if
A+B=X+Y then
A-X+Y+A=X+Y becomes
2A=2X or A=X
and if
A+B=X+Y then
X-Y+B+B=X+Y becomes
2B=2Y or B=Y

Answer 2

取决于数字类型。对于float，您无法得出A = X和B = Y。

假设A = 1; B = Positive Infinity; X = 2; Y = Positive Infinity;

然后A-B = X-Y = Negative Infinity; A+B = X+Y = Positive Infinity; A/B = X/Y = 0; A*B = X*Y = Positive Infinity;